Search this site
| Written by huddy |
| Tuesday, 23 February 2010 09:19 |
|
Upgrading your Graphics Card - Part 1 : Choosing your Card
Choosing a new graphics card can confussing at the best of times; which card is best? Buy now or wait? Nvidia or ATI? How much do I spend? What's bottlenecking??. It's a mine field. My guide below will hopefully answer some of your questions.. Read on :
When ground breaking games such as Doom arrived on the PC during the early nineties, no one then could have imagined how games would have advanced the way they have over the years and there’s still not slowdown. Today, thanks to evolving technology and advanced graphical acceleration, we can enjoy stunning visual experiences with games such as Far Cry 2, Fallout 3 and Crysis, to name a few. These cutting edge games are filled with interactive life like environments and look truly amazing. At times it’s hard to believe that these are just computer generated images and games.
These improvements come at a cost though. As games have become more complicated and demanding, then so too has the hardware that runs them and since the graphics card is mostly responsible producing these visuals then it has become the pinnacle of any gaming PC. An aging or underperforming card will result in loss of visual features such as shading, textures, distance drawing, anti-aliasing and so on (we’ll explain these later). The absence of which will make any game look rather dull looking, unrealistic or even unplayable. When you have reached this critical point then it may be necessary to start thinking of upgrading your graphics card. All of a sudden, the graphics card you bought last year which was once bleeding edge technology becomes as useful as an empty baked bean tin. The hard hitting reality of graphics cards and the whole business of PC gaming as a hobby hits home.
However, choosing a new graphics card can be quite a minefield and expensive too. If not chosen wisely, buying the wrong card may provide disappointing results or be a complete waste of money. Going out buying the most expensive or cheapest card isn’t always the right answer and not everyone has the same system configuration so what may work for one person, may not work for you. It’s no wonder of all the components in a PC the graphics card is arguably the most talked about subject in the PC gaming community
I can’t tell you which card you should or shouldn’t buy because it really depends on various factors like your usage, existing hardware, budget etc. However, I’ll try and point you in the right direction to help.
Firstly, if you have never bought a graphics card before then let me tell you one thing about graphics cards that you should be prepared for. The price of graphics cards drop and depreciate quicker than any other product you are going to spend on your PC. The fast turnaround of newer and faster cards dictates both current prices and the prices of older cards too. A card you paid £300 for last year might only be worth £80 next. It sounds harsh but unfortunately very true. Keep this in mind when you re-visit an e-tailer six month later to find the card you bought is so much cheaper.
If you have bought a graphics card before then you may already know that there are good and bad times to buy graphics cards. The market is largely dictated by the leading card manufacturers who are always competing for biggest slice of the market and are always pushing the boundaries of new technology. It’s not uncommon to see a new range of cards being released every couple of months but generally, a new generation of cards come to surface at least once a year. Ironically, the best time to buy new graphics card is when a new launch is expected as traders try to shift stock ans card prices plumet and you may land a bargain. Be fully aware though, that such cards are quickly superseded so make sure whatever card you buy will play the games you want now and for the foreable future otherwise your purchase could be false economy if six months later you are looking for new one.
The main key to upgrading your card is not what it will be worth tomorrow but what its worth to you as a user today and the value for money you’ll get out of it long term. I say, something is only worth the money if youenjoy and get good use out of it otherwise it’s a waste.
By understanding the basic workings of your graphics card may give you some better idea as to what card is best for you. I’m only going to cover the very basics because the graphics card is quite a complicated beast and the inner workings aren’t relevant to your decision making. However, understanding what it does rather then why, will.
Every PC or laptop has the ability of displaying graphics; text, images and even some basic video footage etc. At the very least, your PC will have some kind of Video Graphics Adaptor (VGA) to send signals from the system to a monitor. The most basic VGA has very little if at all graphics processing power. They will be enough to show predefined images and basic video clips but if you buy a game, there is a good chance the game won’t start because the software requires extra processes to create a dynamic image. This can only be done through a graphics accelerator, which is usually provided by a graphics card.
The graphics card is simply an expansion card that fits into one of your systems expansion slot. Its purpose is to take over the job of producing graphics from the CPU thus serving as a dedicated yet parallel process.
This in turn enables the system to work faster at producing images. When playing games, the graphics card will produce a set of rendered images called frames which when shown is sequence produces a moving image, a bit like a flip-book. In order for you to see these frames seamlessly without any flicker, the system has to generate and display 24 successive frames per second (fps). If a card fails to produce this rate of fps, then you will have to lower the detail of the game or lower the resolution of the screen. Even then it may not be enough which is a good sign that you may need an upgrade.
Each frame is generated by a series of polygons which are dynamically created. The graphics processor will calculate and alter the geometry of these polygons to make a new frame giving the appearance the image is moving. The greater the number of polygons then the tighter they are together will produce better and smoother image production. But this is just the start. Textures, shading, lighting, colour etc all have to be added give the image a realistic look.
This is a complicated process and the more work the graphics card has to do then the greater the strain on performance. If a card fails to produce the required rate of frames per second, then you will have to start lowering the level of detail in the game or lower the resolution of the screen or both. Even then it may not be enough which is a good sign that you may need an upgrade.
The attraction to gaming enthusiasts is to play the latest games at the highest settings that their system will allow in order to achieve the highest frame rate. However, not everyone has the latest technology nor do they have bottomless pockets to suite.
The best place to start is by looking at the components you have already or the components you intend to buy with the card because this will in all intense and purposes dictate the card you should be buying. You will need to check for its compatibility, decide what the card will be used for, whether or not the card will be used to its full potential and finally, you need to set yourself a budget.
Failure to do your research before you buy could be costly mistake but can be avoided with a few simple checks:
Your graphics card will need to be inserted in to a slot on the motherboard so you will need to check that card is compatible. Although it’s physically impossible to insert the wrong card into the machine, it’s best not to buy the wrong card in the first place. So you will need to identify which one you have.
As of writing there are 3 types of slots that can be used to host a graphics card:
PCI – Peripheral Component Interconnect. This replaced both the ISA and VESA local bus but it too has been superseded. Unless you have a very low end PC and video requirements then any PCI video card is best avoided.
AGP - Accelerated Graphics Port was introduced in 2004 and provided the first dedicated high speed video interface for faster 3d acceleration. However, faster PCI Express provides greater bandwidth and has superseded AGP. That said you may find plenty of PCs still using this port and changing or upgrading to PCI express isn’t possible without changing the motherboard.
PCI-e – PCI express has replaced both the standard PCI and AGP ports listed above. This technology uses point-to-point serial links to communicate with the motherboard rather than shared link thus providing a significant increase in data traffic (bandwidth) over lanes. Typically, graphics cards today will use 8/16 lanes for data transfer.
To confuse things a bit more, there are different version of PCI-e which characterises their signalling mode and bandwidth. However, all are backward compatible with previous version. 1x. = 250 MB/s per lane or 4GB/s for a 16 land slot
V2.0 = 500 MB/s per lane or 8 GB/s for a 16 lane slot V3.0 = 1 GB/s per lane or 16 GB/s for a 16 lane slot  The size differences between PCI-e (Left) and AGP (Right) are quite apparent
In some cases (no pun intended) you may need to check your case to make sure there is enough room to host a new card. The problem with some smaller cases combined with the fact that card are getting longer, means the space between card and the case drive bays has been reduced meaning you may not have enough room.
Before you buy, take a moment to measure the distance between the slot cover of the PCI-e and the drive bays behind then check the dimensions of your potential purchase.
Make sure you have enough room for power connections and cable connections too. If things are a little cramped, you may have to reconsider your purchase and/or buy a new case.
 The above image shows the three very different cards with very different lengths
As modern graphics cards have evolved then so too have the power their power requirements, cables and connectors. Be sure you make all necessary checks before you buy.
Check the Graphics card manufacturers website for the power requirement of the card you intend to purchase. Check if this is much different to what you have already and the PSU can cope with the demands with all the other components too.
If you have an old or low wattage PSU, the chances are that it might not provide the power it needs. If you don’t know the power of your PSU, you may have to open your case side and have a look. All PSUs will have a sticker detailing the power specifications including total wattage and ampage. If not, then check the PSU manufacturers website. Make sure these meet or exceed your systems requirements.
Check also the PSU is supplying the correct ampage too. This is often overlooked and can present stability problems of their own. Again, check the minimum requirements for the card and cross check this with the PSU specification as you did the with the wattage.
For example; you have a Corsair HX520 and wish to add an ATI 5770.
ATI recommend a power supply to have (in total accumulated) at least 40 Amps available on the +12 volts rails. In which case, the PSU is fine.
However, if you add another 5770 in Crossfire ATI recommends a power supply needs to have (in total accumulated) at least 55 Amps available on the +12 volts rails. The PSU therefore is not adequate for the job.
Most modern graphics cards are PCI-e cards and will most likely require one or two PCI-e 6/8 pins power connectors depending on how powerful the card is. These cards will take 75w through the PCI-e slot and a further 75w/150w through each 6 or 8 pin auxiliary power connections respectively. So a single PCI-e card with two 6pin connectors will consume 225w. If you don’t have a designated PCI-e connectors then don’t panic, you can purchase Molex to PCI-e power adaptors separately from any good electronics retail but in my opinion this is something I’d personally avoid.
 Molex to 6/8pin conversions are available but check you PSU is capable of running your card first.
Bear in mind though, even a high end PSU with weak 12v supplies (or rails) is almost certainly going to give you problems before you even start so make sure your PSU is of good health. You can follow my simple guide here. My advice is never skimp on the quality or the output on a PSU. Aim for an efficient PSU that’s at least 20% over your total system power requirements.
If you have any doubts, use this calculator to give you some idea as to your power requirements.
Direct X is a series of Microsoft Application Programming Interfaces (APIs) that allow the programmer of an application to use the built in functions to handle graphical tasks in Windows.
Historically, each new Microsoft release has come with its own new version of Direct X. This is important factor because not all graphics cards will be directly compatible with the current version of Direct X. Something to bear in mind if you are upgrading your Microsoft Operating System too.
Windows 7 for example, is shipped with Direct X version 11 which means you will need a direct X 11 compatible video card (such as the ATI 5* series) to take advantage of its features. However, Direct X and the card are backward compatible meaning that older cards will work with newer version of Direct X and newer cards will work with older Direct X versions albeit with some functions degraded. If you don’t think you’ll be upgrading your Windows Operating System for a few years, say from Vista (direct X 10) to Windows 7 (direct X 11) then you may grab a bargain with older cards but in my opinion, buy a card with that is compatible with the current Operating System and Direct X for some future proofing.
Screen Resolution
You will need to determine what resolution you’ll be playing games at. i.e. the size of the viewable area of your screen. This is a very important phase of the selection process and is often overlooked as it will determine what card you should be looking at and the amount of Video RAM needed (we’ll discuss video RAM next).
The screen size, or resolution is fixed by the maximum number of pixels (px) the monitor can present to give you an image. A HD 1080p TV for example, has the maximum of 1920px by 1080px. However, unlike a TV which is sent a pre-defined signal from its source, the graphics card will be responsible for producing detailed and refined images which will fit on to the set resolution. However, the combination of these complications means your card will have to work harder to produce the desired image.
The greater these demands the greater the power required which will mean bigger bucks. But this doesn’t mean you should go out and buy the biggest and meanest graphics card or sell your mother to fund it. Although that maybe the case if you do have bigger screens. You’ll need to choose a graphics card that best suits your monitor and your gaming requirements. Unless of course you are thinking of changing your screen at the same time. Either which, be sure to select a card that pairs up sensibly with your screen.
The reason I choose the word sensibly is important because if you have a monitor with resolutions of 1920px by 1200px or more then you may need to spend more buying a high end card that supports that resolution i.e. larger video RAM and high frequencies etc. A low end card will struggle (if at all) to produce playable images at these higher resolution.
Conversely, if you are happy playing games at lower resolutions because you don’t want to change your monitor, then you have no reason to buy a high end card. Unless you change your monitor then it will never be used to its full potential and is a complete waste of money. Low to mid-range cards will perform just as well on the lower end resolutions at a fraction of the cost. The GPU access data directly from the Video RAM rather than having to access system RAM which would be slower. That’s not to say that buying a card with large video RAM will work any faster than those with less. Larger amounts of Video RAM only come into their own when you play games at higher resolutions (as discussed above). If your monitor doesn’t support resolutions of 1920px by 1200px or greater, for example, then there is little point in buying a 1GB video card so you can save some money here.
Bear in mind too, that Video RAM is often mapped to main memory so if you are running a system with 4GB of main memory, then a video card with say 1GG of video RAM will use its equivalent amount of main memory leaving you with just 3GB.
What is important is the speed at which the RAM runs at. This isn’t a compatibility factor but the greater the speed of Video RAM then the better the card will perform and some manufactures will have variants of RAM speeds.
If you research hard enough, it won’t be too long before you hear the term CPU bottlenecking. Basically, a video card is sent instructions from the CPU. If the CPU isn’t quick enough, then the video card will under perform because the CPU will be restricting the data flow to the card and thus causing a bottleneck.
I said at the very beginning that it’s important to understand the system in which the card will be used in. Just adding a new card isn’t always the end of the story. If you introduce a shinny new £400 graphics card to an aging or low-end CPU, then although the card may work, it will be seriously underachieving and overkill. You might have been better off buying a budget card which will result in similar performance at half the cost. This is what I meant by buying the most expensive card won’t always produce the best results. If you really must have the greatest and best, you should look at a new system with a faster CPU.
It won’t be too long before you hear two phases: Sli (Scaleable Linked Interface) and Crossfire. Basically they are both the ability to run two graphics card in parallel providing even more willy waving grunt. Both SLi (Nvidia) and Crossfire (AMD>ATI) both use distinct PCI-e slots so are motherboard dependant. Until recently, motherboards would only run or the other but this limitation has now been discarded in recent chipsets.
The advantage of running two graphics cards is the extra performance it provides especially when running games at high resolutions say at 2560 x 2048 (QSXGA) with a dual monitor configuration. Don’t be fooled by the theory that having two cards is twice the performance. This is not always the case. SLi and Crossfire support in games varies between 0%, 30% and near 100% performance scaling depending on latest driver profiles and game support.
The disadvantage is of course the cost. Buying two cards is no cheap outlay and doubles the impact of depreciation I mentioned earlier. It may also mean a new motherboard and a decent PSU with no less than 850w total output. There is of course driver and game support which over the years have improved but there are still the odd problems.
I’m not going to cover SLi or crossfire any further in this guide but I just wanted to give you some insight because it’s something you’re bound to come across.
As video card and monitors have evolved then it’s no surprise that the connection have too and there are many types to consider. Again, this decision goes back to what type of monitor you are using and it connectivity to your PC.
VGA – Video Graphics Array
VGA is an analogue connector cable of display low to mid range resolutions. Although these have been superseded, there still pretty common with any CRTs floating around or budget TFTS.
DVI – Digital Visual Interface.
DVI Connectors normally pass native digital signals between devices. Additional pin orientation can also mean two set of data signals and same signal in Analogue form found on the VGA which allows for easy adaption when connecting VGA monitors to DVI.
There are four types of DVI connectors that although look the same, they have different pin combinations:
DVI-D Supports uncompressed digital video signals only. These digital signals avoid the degradation of due to electrical noise and therefore produce a far superior image quality of that of analogue (single and dual link)
DVI-I Supports both digital and analogue signals (single and dual link)
DVI-A Supports analogue signals only
DVI M1-DA Supports both digital and analogue signal in dual link with additional USB support
I have mentioned above the terms single and dual link. Both determine the amount of data that gets pushed through. A single link has a bandwidth of 3.96Gbit/s and supports resolutions of up to 1915px x 1436px on a 4:3 ratio at 60Hz. A dual link interface will an addition six pins which provide greater throughput of data with a bandwidth of 7.92Gbits/s, thus capable of displaying much higher resolutions.
HDMI – High Definition Media Interface
HDMI is very much like DVI except it transmits uncompressed digital audio data as well as video digital data therefore runs through a higher bandwidth of 10.2Gbit/s.
Although this interface has been around for awhile now, it’s only been recently that that have been appearing on monitors and video cards. The reason for this is it’s most likely that PC have separate audio interfaces and therefore don’t actually require the extra data throughput. However, if your connecting your PC to a HD 32’ TV, then it might be worth it
DisplayPort
This is VESA standard digital interface and carries both clock and optional sound signals. It provides a 5.184, 8.64 or 17.2Gbps channel for high resolutions with a single cable. It also supports 128-bit AES DisplayPort Content Protection (DPCP) as well as 40-bit High bandwidth Content Protection (HDCP). More importantly, it’s completely royalty free meaning reduced cost for graphics card manufactures. Certainly one to keep an eye on but don’t threat over it. The presence of the above is too high at the moment.
Like most things at the end of the day it all comes down to money. How much you are prepared to spend of course depends on your disposable income but bear in mind the things we’ve already discussed, such buying buget cards and cards that are simply an “overkill”. Remember too that your new card will depreciate at some point in the near future and buying the most expensive doesn’t mean it’s the best card or the best card for you. Conversely, spending too little may result in significant performance loss, particularly if you have a larger screen.
If you intend just playing older or simple games you may not need to spend that much at all as they are less grahically demending than today's resource hungry games . A new low-end or bargain second hand card may suit you and your pocket.
When deciding you budget, bear in mind that you may need to upgrade other components too. The cost can add up so make sure the upgrade is worth the extra money being spent.
There are various manufacturers of GPUs and graphics cards including AMD (who bought out ATI), Nvidia, and more recently Intel but it’s the two aforementioned that dominate the market.
Choosing which is really irrelevant unless you are considering running dual graphics cards (covered earlier). The competition between the two has been rife for years and both are constantly battling for top dog in the market. Who said competition is a bad thing? Of course, there are those that favour one particular manufacturer over the other and will stick to them no matter what the competition has to offer. There may be genuine reasons as to why this is. It might be that they had a bad experience with a new card that was DOA (Dead on Arrival), driver issues or simply stick to their comfort zone i.e. familiar territory is a wonderful ally. However, don’t let these “fanboys” or anyone influence your decision unless there is a good reason for doing so. It's good to keep an open mind and it's your money after all.
Don’t read too much into the specification differences between Nvidia and ATI. Clock, memory and shader speeds along with the number of stream processors etc between the two manufacturers are incomparable because of differences in the architecture and design. It's this difference that causes so much debate within the community as comparisons can only be made by real time benchmarking, which of course is limited to other factors like the CPU and chipsets etc..
I mentioned earlier, that the leading video card manufacturers typically release a new generation of graphics cards every year and interim revisions between. Typically, new generation of graphics card normally introduce groundbreaking GPU architecture, improved manufacturing process and possible new features such as DirectX. In turn, this means they should be far superior than their predecessors. This generates are frenzy of excitement on the technical forums.
With each generation comes a range have a family of budget, mid-range and high products to suit every pocket and requirement. Not everyone is a gamer and not everyone has £400 to spend on such luxury. To make things even more complicated, you’ll find lots of revisions and variants which are normally the same GPU but with higher clock speeds etc.
Both ATI and NVIDIA have a naming convention to help identify which cards are what but this isn’t always clear cut as it would first appear.
ATI Naming
ATI has always branded its desktop graphics card as RADEON followed by there model mnemonic: ATI Radeon Series-family-model
The series is the generation of the card. The family denotes whether the card is budget, mid-range or high end and each will have their own GPU and chipset. The model is the variant within the family and is normally the same GPU within the family but may have different clock, memory and shader speeds etc. This ensures a rich array of cards with different capabilities and of course price.
For example, the ATI Radeon HD 5870 - From this information I know this is a high end product of the ATI Radeon series 5 card (DX11 compatible).
By contrast the ATI Radeon HD 5770 is the top end of the mid-range cards. The following link is the current range of ATI series 5 cards: http://www.amd.com/us/products/deskt...n-hd-5000.aspx
NVidia naming
NVIDIA follow a similar naming pattern to that of ATI but has revised its naming convention changed after the 9 series. Again just like ATI, NVIDIA has always branded its desktop graphics card as GeForce followed by there model mnemonic:
Nvidia Geforce Series-family-model
Nvidia Geforce model-series- family (After 9 series and to date)
Regardless of which, both conventions use the same mnemonics and have the same meaning. The series is the generation of the card. The family denotes whether the card is budget, mid-range or high end and each will have their own GPU and chipset. The model is the variant within the family and is normally the same card within the family but may have different clock, memory and shader speeds etc. This ensures a rich array of cards with different capabilities and of course price.
For example, the Nvidia Geforce 9800GTX - From this information I know this is a high end product of the Geforce 9 series card (DX9 compatible) with higher clock speeds of other members in the same group. A GT will have lower clock speeds..
The second example is the Nvidia Geforce GTX 260 - This information tells me that this is the mid-range series 2 product.
Some manufacturers, such as Asus and HIS, will change the reference cooler with a non-reference design to improve cooling and there by increasing their ability to clock higher than the standard specifications. In which case, you may find further modifiers and the end of the reference.
Sapphire ATI Radeon HD 5870 Vapor-X indicates the card is using a non-reference “Vapour-X” cooling system profited.
Not all new generation cards will out perform older generations. An ATI Radeon HD4870 will perform on par with the newer ATI Radeon HD5770 and this is known as a side step. Basically, it’s a newer card with all the new features it brings but with the same performance. Conversely, an ATI Radeon HD4890 will out perform the newer ATI Radeon HD5770 out right.
Many people have fallen victim of this expecting their upgrade to yield higher performance gains but have been disappointed. So be careful, bigger numbers don’t always mean better performance.
For those that like skipping to the end, here is a summary of what you should be looking for when choosing and buying a new card.
I hope this guide helps
Please email if you feel there’s something I’ve missed
|
| Last Updated on Thursday, 25 March 2010 12:56 |