Praetor

Section 03 - Long and Painful: What do I need to know to pick out a good videocard?
There are four steps to picking out a good videocard:

1. Define your requirements. This one is pretty straight-forward: what kind of features or performance do you need/want from your videocard? Do you want to be able to play the latest and greatest games on the highest settings? Do you want to have video capture capabilities? Do you want a super-silent computer? Or something else? By defining what your needs are you can cut down on the number of possible products to consider.
2. How much money do you have to work with? Yes we would all like to be able to spend a zillion dollars in every area of our computer to have the best system possible but that's not an option generally available to us. By putting a limitation on the price tag we can further reduce the number of options to consider
3. Indirect considerations There are three considerations here (1) people who want silent computers (2) people who want to do fancy things like overclock or unlock pipes and (3) people who want to game on LCD monitors
4. Do some more research

Part 1: Defining your requirements
The questions we are trying to answer with this step are:

• How much graphical horsepower do you need? Here are a few scenarios:
  • A machine that will just be used for work, movies, email, chatting will not have virtually zero graphical horsepower requirements
  • A machine that will serve as a "general purpose" computer that will encounter the occasional game will have minimal gaming requirements
  • A machine that will be playing the latest and greatest games will have a very high gaming requirement
  • A machine that will be used in for the purposes of doing animation or rendering will have a very high workstation requirement
  • A machine that will be used in t home theater type setup where the primary screen is the TV/projector will have a VIVO/TV/Media requirement and as a secondary requirement, it would be benificial if the videocard was relatively silent
  • A machine where the user intends to maximize the performance of each and every component through unlocking or overclocking will have thermal requirements
• What type of horsepower do you need?
  • Gaming?
  • Professional?
  • Media?
  • Other?
• What other requirements do you need?
  • Silent?
  • Will thermal management be an issue?
  • Power constraints?
  • Connectivity constraints?

Part 2: How much money do you have to work with?
This step should be pretty self-explainatory.

Step 3: Indirect Considerations

• If you plan on gaming on a LCD, be aware that LCDs have something known as a native resolution. If you play the game (or do anything really) at anything other than this native resolution then the image quality will be very poor. If you own an LCD with a relatively high native resolution of say 1280x1024, and you want to play a game such as FEAR (which is graphcially intense in an of itself) then note that your videocard must be able to handle that game at 1280x1024. People on CRTs (aka "normal monitors") dont need to worry about this since their displays are not limited to a single resolution.
• If you plan on buying a high powered videocard make sure your computer can actually power the card reliably. Videocard manufacturers and many people will say "get a 500W PSU" or something to that effect -- this is absolutely useless since a bad 500W PSU will not be able to reliably power your videocard. This consideration is doubly important for people who are installing a new highend videocard into an OEM machine (i.e., Dell, HP, Compaq, IBM etc) where the quality of the included PSU is questionable at best
• Although this is not nearly an issue now as it was maybe a few years ago, but some games have certain hardware requirements (i.e.,"You need a DirectX8 videocard to play this game"). The common scenario was people bought budget videocards (i.e., GeForce 4 MX which is a DirectX7 card) and they wondered why they couldnt play a game that required DirectX8. Simply going to Microsoft.com and downloading the latest DirectX does NOT mean your hardware supports that version of DirectX
• If you're intending to make a shuttlebox or HTPC, please be aware of heat constraints: those small boxes are often not well ventilated enough to handle the heat output of the higherend cards

Step 4: Do some more research
When you've narrowed down your cards, do some research on them! Dont make the mistake of trusting customer reviews: many times people will have a problem with a product (usually due to them skipping over step 3 and forgetting something) and they will blame the product. Instead, do your research by searching for comments from well established hardware review sites aka people who know what they are talking about.

An important step here is to recognize bias and fanboyism when you see it. For some reason kids (usually) tend to think that one company sucks or another company sucks without having any technical reason to back it up. Sure having opinions is cool, but just like you should not trust customer reviews, take people's experiences with a grain of salt: just because one person had a bad experience does not mean you will.

Now once you've done all this you should have a pretty small set of videocards to pick from: feel free to post your selection here (along with your budget and requirements) and you'll generally get a response or two from people indicating what route they think you should take. Again with the "grain of salt" ... look for reasons so that you can deal with facts and not just opinions.

Lastly, have a look at the VFAQ to address some pretty common questions and concerns that people looking to buy videocards have.

A bit more detail...
Gamer
A good gaming card generally strives to feature the best of the best and to have the most of it; some stuff to shoot for when picking out a gaming card:

• Pipelines. Most commonly listed as "pixel pipelines" or "programmable shaders", the number of pipelines acts as the limiting factor on how many simultaneous shader programs can be run. Although cards do exist that do not have these shader pipelines, you are much better off getting a card with at least some pipelines. Unless you are severely price limited, you absolute minimum number of pipelines you should shoot for in a gaming card is 4. Those looking for midrange cards should generally shoot for cards with 8-12 pixel pipelines and the high end gamers should be looking to buy cards with more than 12 pipelines.
• Clockspeed. Just like with processors, the higher the clockspeed, the faster the card and the smoother the gameplay so strive to get the fastest possible clock as financially feasible.
• Bandwidth. All the GPU processing power in the world isn't going to be very useful if the processor is starved for data and users looking for high end cards will find that performance, as complexity increases, generally is limited by the memory bandwidth. Now how to pick out a card with good/high bandwidth? There are two considerations:
  1. The 'bit-size' (technically called memory addrerssing bus width) of the video card. Budget cards often feature 64bit memory meaning for each memory clock cycle, 64bits (8bytes) can be processed at a time. Midrange cards will generally feature a 128bit memory structure (meaning each clock cycle will allow for 16bytes to be processed) and high end cards almost always feature 256bit memory structures (for 32bytes per clock cycle).
  2. The memory clockspeed -- for lower-end cards this information is notoriously hard to come by and often, a quick Google search will return a dozen [potentially] conflicting results and interpreting them correctly takes abit of intuition/experience. The reason for the complexity is that marketing people know that 'the bigger number sells' and as such, they will often list the memory speed using the "DDR value" rather than the actual speed (what this DDR thing is, is that for each clock pulse, instead of sending one single per pulse, you send two per pulse and get twice the work done in the same amount of time; see RAM 101 for more on this). The actual memory clock speed will always be the smaller of the two values and to be specific, it will be exactly half (i.e., for a videocard advertised with 700MHz 'effective speed', it will actually be running at 350MHz). In general, you'll want a higher memory clock speed.
  Now to determine the memory bandwidth that a specific card has, simply peform the following calculation:
  
  Bandwidth = BitSize x MemoryClockSpeed ÷ 4
  So a quick example before moving on, a video chip like the nVidia 6800GT which features 256bit memory running at 500MHz (sometimes noted as "DDR1000", "1000MHz effective speed" or even worse, "1000MHz") will have 32GB/s of bandwidth (256 x 500 ÷ 4 = 32000MB/s which is roughly 32GB/s).
• Memory amount and type: in addition to the bit-size of the memory, you'll also want to get the most and most advanced type of memory that you can for your gaming card. For the most part, even low-budget gamers should strive to avoid 64MB cards as much as possible (although that really should be your ceiling unless you are really budget constrained -- something i'll deal with later); gamers looking for mid and high end parts should make 128MB of memory as their minimum. Do note that videocards with 512MB of onboard memory do exist however there has yet to be significant/noticeable performance gains from investing into that platform.
  
  As for memory type and getting the most advanced type, video memory is slightly different than normal system memory (which marketing people love because there is more jargon to toss at the consumer). In the context of videocards there are currently three commonly found types of memory:
  • DDR (sometimes denoted as GDDR, DDR1, GDDR1 etc)
  • DDR2 (sometimes denoted as DDR-II, GDDR2, GDDR-II etc): the difference here is DDR2 hit higher clockspeeds (thus offering better performance) however the memory chips still ran at the same 2.5v as the original DDR and so heat became an issue.
  • DDR3 (mote commonly denoted as GDDR3 but other variants exist) solves the heat issue that DDR2 had by lowering the signalling voltage to 1.8-2.0v.
  Performance-wise, clock-for-clock all the types of memories are the same (i.e., 500MHz DDR and 500MHz GDDR3 will yield pretty much the same results). To avoid confusion the remainder of this guide will make use of the notation: DDR, DDR-II, GDDR3.
  
• Futureproof. Although this is somewhat impossible given the fast turnarounds in the industry, you can somewhat make wise decisions by purachsing cards that may allow you to do more advanced things later on (i.e., SLI, overclocking friendly cards etc). For this most part, this isnt nearly a big consideration as the above points. For those looking to buy a new videocard, the only notceable impact here is deciding between AGP and PCIE: you should strive to get a PCIE system where possible as AGP will be phased out (in fact, it is all but phased out).
• API Support. Marketing people like to play with words and one word they enjoy is "compatible"; an example of this is with a GeForce4MX, the marketing will say "DirectX9 compatible". So far it may seem that there is nothing wrong with the statement however the hardware on the GeForce4MX is DirectX7 class. So how does this work (and are they lying)?! What this means is that when a game issues a DirectX7 command the videocard will respond as expected however when the game issues a DirectX8 (or better) command, the card is not capable of executing that command and in best case scenario, it will just sit there being dumb (more likely it'll crap out on you). The marketing people, however, aren't lying to you: the card is [literally] compatible with DirectX9 -- what they mean is that you can install DirectX9 onto the computer and the graphics card wont have a problem with it. Translation? It's meaningless goobble-dee-goop that marketing people throw at the consumer.

For gaming cards, expect to spend upwards of 75USD for anything passable. Upper limits are in excess of $1000 for complete configurations.

Mainstream Cards
By mainstream I mean videocards you would find in an office computer or a basic no-games computer. The line between very-low-budget-gaming cards and mainstream cards is a thin grey one: for the most part, mainstream cards are the low budget gaming cards. Since there is no gaming to be done one these machines, any cheap videocard will be sufficient. For the most part, expect to spend $30-50USD on a mainstream card. As an alternative that offers less fuss (but often less performance/flexibility), you might consider getting a motherboard with a built in videocard: the motherboard will probably cost an extra $5-10USD but that is offset by not having to buy a videocard.
Theater/HTPC
Buying a videocard for a 'movie machine' generally places the emphasis on three points:

• Featureset. What you should generally be looking for here is video in/out features as well as TV-related features. The biggest, baddest GPU isnt gonna be very useful as a HTPC (home-theater PC)( card if it cant interact with the TV (which for the most part is still the dominant video display in a home theater setup). Being able to interface with VCRs etc is also useful
• Cool and Quiet A fancy videocard, more often than not, is likely to generate tons of heat which will have to be dealt with. Normally this isnt much of an issue however in theater systems (which can/often are employed in small cases, airflow is an issue and as such, it's better to have a cool card to start with). For those concerned about noise, fans generate noise and having a cool card to start with often means the fan can spin at a lower speed (and thus generate less noise).

Workstation/Professional
Unlike gamer cards where performance between various benchmarks can vary wildly, workstation cards are bit more consistent (with much more well established benchmarks). For the most part the determining factor will be

• Amount and type of memory. Same as for a gaming card, the more memory the better and the more advanced the memory, the better.
• Fillrate All other things being equal, a card with more bandwidth willl give a card a greater fillrate, both geometric and texture

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