As you've stated, deciphering the mess that surrounds display card purchase decisions is extremely difficult. Terminology is confusing, and product specifications sheets often don't include the information you wish to see. The following is intended to be a guide to help you and other readers wade through it all.
How do I choose a Video Card?
a novel by Terry O'Shanassy
What do the letters mean?
There are no 'Standards' for the letters included in product model numbers. Each graphics chip manufacturer uses their own system, and some graphics card manufacturers (LeadTek is a prime example) use a completely different terminology of their own. In common use, however, the following is usually a fair guide:
nVidia FX cards
XT: This lettering is used to indicate the lowest performance variety of a model number.
No lettering: The 'vanilla' version of a particular card model number.
Ultra: The highest performing variety of a particular model number. It will be clocked higher than the 'vanilla' version and perform faster.
Good buys:
FX5900XT - the 'cut-down' version of the FX5900 is a good choice in the mid-price range, and although it is usually a bit more expensive, it certainly outperforms the Radeon 9600XT. Can be purchased for around $300
FX5950 Ultra - Perhaps the most expensive of the 'high-end' cards available, but it has performance comparable to a Radeon 9800XT, and does not have the compatibility problems that many users have reported for Radeon cards (driver issues, failure to work with 'AGP Fast Writes' etc.) Can be purchased for around $650
ATi Radeon cards:
SE: Indicates the 'cut-down' version of a particular card's model number. Has slower response memory chips, and usually has features disabled.
No lettering included: The stock specifications for a particular card number
Pro: A full featured and higher clocked instance of a particular card number
XT: The highest clocked instance of a particular card model number.
Good buys:
Radeon 9600XT - A very good performing card in the mid price range. Can be purchased for around $240
Radeon 9800 Pro - Now available at the high-end of the mid-price range if you look hard enough, this one is only marginally slower than a Radeon 9800XT, at a much lower price. Can be purchased for around $390
In general, ATi Radeon based cards are faster than their nVidia counterparts, but the nVidia FX based cards are less problematic for inexperienced users.
Video RAM Speed:
Generally, it's better to look for video memory with a higher clockspeed, but it's also important, as Dave has indicated, to consider the 'response time' of the video memory modules included on a card. A good analogy is the 'Drag Racing Strip' in the auto world. A car might have a higher top speed, but it's probably going to be beaten down the quarter mile by a car with quicker initial acceleration!
The response time of video memory is measured in nanoseconds, and the figure is seldom included in product specifications. Perhaps the only sure way to know what the response time of the memory chips used on a particular card is to actually look at it and note down the identification number printed on the chips. The last two digits of that number will generally indicate the response time, i.e. xxxxxxxxxx22 indicates 2.2 nanosecond memory.
Amount:
128 megabytes of video RAM should be considered the 'standard' for display cards intended for use with today's PC video games. Anything less is becoming rather restrictive, and could impede the performance of your games.
I've really come across no reports of instances where more than 128M of video memory is necessary for today's games, and many, many reports of 256M cards where performance has suffered due to the lower response time memory chips included on them. There are, certainly, some instances of memory chips with a lower response time being included on some mid-range 256M cards, but so far as I'm aware it's a 'hit and miss' affair regarding the chances of you getting your hands on one. I've not really heard of instances where faster response memory is used as a matter of course, and such instances seem to be the result of memory chip availability at the time of manufacture. (If any reader knows that I am wrong here, please correct me and point us in the direction of your source of information.)
For the very 'high-end' display cards however, such as the Radeon 9800XT or the nVidia 5950 Ultra, you'll find that the more responsive chips are usually included regardless of whether the card offer 128M of video RAM or 256M of video RAM. The same situation probably exists for the Radeon 9800 pro and the nVidia 5900 Ultra as well.
The other point to consider is that, unless the display card you purchase is at the very high end of what's currently available, when the time comes that Games will require more than 128M of video memory, your card might just be too slow to run them effectively anyway.
"Next Generation Display Cards"**
The new lines of nVidia's 6800 series , based on the NV40 graphics processor, and ATi's X800 series, based on the R420 graphics processor, have already been announced and launched, and should be appearing for purchase very soon indeed. They are certainly at least twice as good as current high-end display cards.
Both these lines of Display cards will be available in AGP versions, although they will possibly will be best suited to the PCIE (PCI Express) interface computers and the games to come. For the purposes of coping with the most recent games and the very demanding ones which will be released over the immediate future, there's no doubt that an AGP version of one of these display cards would be the best choice of all for current systems, if future-proofing for Games is the goal. If your system is up to coping with one of them that is! The new cards, nVidia's in particular, are quite demanding of your system, and may even require a power supply unit upgrade!
Considering Future Proofing and your Purchase Decision
There are a few factors to take into consideration when you're about to upgrade your display card, and the product specifications of current display cards is only one area of consideration.
The specifications of your PC itself should be a factor. How powerful is it? How recently have you upgraded and to what? The display card market itself is another consideration again. Is it suitable for you to upgrade to a current generation display card now, or should you wait for a 'next generation' display card. Those have been already announced, and should be available for purchase quite soon. The PC market itself is another consideration. We are confronting a change from systems using Socket 'A' (AMD) and Socket 478 (Intel) with PCI and AGP slots to systems using Socket 939 (AMD) and LGA 775 (Intel) with PCIE slots. The 'next generation' display cards will doubtless come into their own when used in combination with those new format systems, but in the interim, transition period there will definitely be AGP versions of the new cards available.
A 'cut-off' point needs to be kept in mind for considering what display card to upgrade to, and I'd suggest that it should be systems which are based on the AMD XP2500+ or better or the Intel Pentium 4 2.4C processors. Beyond that, a system could be perhaps be considered as 'high performance' and below that as 'Low Performance'. That might sound a bit extreme to some readers, but remember we are talking in terms of 'future-proofing' for PC Gaming!
I'd also suggest that systems which are based on processors Below a Pentium 1.4 GHz or a pre Athlon XP AMD processor should be perhaps considered as 'inadequate' in terms of Future Gaming potential. Here are some suggestions to consider, based on those criteria:
'Inadequate systems"
If that tired old system of yours doesn't even have an AGP slot in it, or only has an AGP 2X slot, then it's time to consider retiring the whole thing for use as an internet terminal! If it's PCI only it won't be suitable for even today's latest games, let alone the ones to come. And if it's AGP 2X then even with a display card upgrade it's probably going to need more than a simple display card upgrade anyway. You'd be best to consider an overall system upgrade.
'Low performance systems"
If your budget is in the mid-price range like Dave's, then adding the best display card you can get for your money is the wisest choice here. But consider the current card you have, and the amount of performance increase the new card would give you. For example, if you currently have a GeForce4 Ti display card, you might get a performance improvement by replacing it with a Radeon 9600XT, but the amount of improvement would be too small to justify the money spent.
There's also not much point to upgrading a lower performance gaming rig with a display card that costs you somewhere around $1000! That money would be better spent in bringing your system up to date, and if you can afford that amount of money on a display card, then you should be able to afford to upgrade your entire gaming rig instead!
"High performance systems"
If your system is recently purchased, or recently upgraded to fir within the 'high performance' category, then there are more options available which would suit you. If your current display card is utter crap then a change to a mid-price range card might suit you. If your budget stretches, and you just can't wait, then a current high-end display card would be a good choice, but as I've indicated previously, don't go spending up around $1000 on a current display card please!
Should you be both able to afford it, and able to wait a little while, then the purchase of an AGP version of one of the 'next generation' display cards should ensure that your system remains quite a capable gaming rig for some time to come yet.
Further Information
Anyway, back to Dave's question after all that. It's where we started from.
Once you've decided pretty much what display card you wish to get, deciphering the minefield of specifications details to compare between manufacturers can become quite a daunting task. And when the information you seek isn't on the specifications sheet, it becomes quite frustrating indeed! But there's information to be had, and you simply need to dig it out.
Google is your best friend!
If you use a bit of thought when you enter search criteria into Google then there's a wealth of information to be found on-line. Try to keep the terms you use to search with as specific as possible for best results. For example, if you enter:
manufacturer fullmodelnumber review Into Google, substituting the details of the card you wish to find out more about, you may turn up extended and detailed reviews of the card in question, which contain the information you seek. If you enter:
manufacturer fullmodelnumber review comparison you may turn up reviews of the card which also compare its performance with other cards available for purchase. In both examples, it's most likely that you'll turn up numerous links to sites which are simply offering the card for sale, rather than providing an extended review discussion of it, but the information will usually be found amongst the results if you care to look through them.
You can also explore the pros and cons of various makes and models of display cards by searching through the contributions to discussion made on various 'enthusiast' Forums to be found on the internet. You may need to register as a member to access some of them, but sites such as
OverClockers Australia Forums or the American site
[H]ard|OCP forums (currently off-line for upgrade at the time of writing) provide a wealth of information and experience amongst the discussions of their membership.
In general, however, you'll find that there's very little actual difference from brand to brand. Almost all manufacturers adhere very closely to 'Reference Specifications' now when making cards. You'll find differences in quality, of course, in things like the PC board material used and the fans and heatsinks fitted, but they don't translate very much at all into performance difference from one manufacturer to another. The major differences in price you find from one manufacturer to another relate to included 'extras' such as games, software and fittings or cables.
That's it for now. I hope some of that will prove helpful to you Dave, and I hope it proves helpful and informative to our readers as well. When those 'next generation' display cards become a marketplace reality and not just a PR battle, hopefully in the near future, you can expect an update to this discussion. For the moment, choose wisely!
Cheers,
Terry O'Shanassy