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Palit 7900GS Review
Graphics Cards
Written by Monkeyman   
Sunday, 22 October 2006 20:19
Article Index
Palit 7900GS Review
Overview and Specification
Packaging and Bundle
The Card
Gaming Performance
All Pages
The midrange sector of graphics cards has always been a mismatch of various cores. Be it the previous generations top end offerings, or the current top range cards in all sorts of configurations, one's often spoilt for choice.

But choosing the right one can often be a bit of a gamble.

Monkeyman shares his thoughts on the 7900GS, a mainstream refresh of the popular G71 GPU.

With a huge variety of high-end cards currently available there has been a bit of a gap in the mid range sector, the 7800GT appeared briefly and was phased out, the X1800XL never had enough grunt to keep up with the Nvidia based solutions and the X1800XT and 7900GT have never been cost effective enough to be classed as budget cards.

All this has changed with the release of the 7900GS, as you will see in the following write-up it has plenty of stock power to play all but the most intensive of games with relative ease and has some serious overclocking potential to bring it in line with some much more expensive cards.


Memory: 256MB GDDR running at 1320MHz
Pixel Pipelines: 20
Vertex Shaders: 7
Core speed: 450MHz

The 7900GS looks very similar in specification the the 7800GT cards that have now all but disappeared, it has the same amount of pipelines and shaders and is still a 24 pipeline card with on pixel pipeline quad disabled, however it is based on the same core as the 7900GTX and not the 7800GTX that the 7800GT is based on.

This new core, G71, is produced on the 90nm production process as opposed to the 110nm of previous cards and seems to overclock slightly better than the 7800 series cards as you will see shortly.

The memory on this particular model of card is 1.4ns Samsung memory rated for around 714Mhz (1428Mhz DDR) which is faster at its stock speed of 1320MHz than the memory chips on the 7800GT giving this card an immediate advantage in speed.

Comparison between the 7800GT and the 7900GS:

Card  Core Memory Clock (MHz) Core Clock (MHz) Pixel Pipelines Vertex Shaders
7800GT G70 1000-1100  450 20 (Out of 24) 7 (Out of 8)
7900GS G71 1320 450 20 (Out of 24) 7 (Out of 8) 

As you can see this is fairly standard packaging with no fancy embossed pictures or the like, this has the benefit of helping to keep production costs down.

The included bundled is as shown in the picture, one game: SpellForce 2, a driver disk and an operating manual, also included but not pictured are the usual molex-PCI-E adapters and the VGA connectors.

As you can see very little is included with the card in comparison to some of the bigger name models, this is more than likely why the card is upto £20 cheaper than the XFX an BFC models, and as you will see further into the review the card does not lack anything else compared to these other cards.

The card has a securely fitted and effective heatsink that has radial fins reaching over but not touching the memory chips, this means that although the memory is passively cooled it does have a good airflow and under normal stock use the memory does not become more than warm to the touch.

The rear of the card is as you would expect, the only prominent feature being the retaining bracket for the heatsink. The attached fan is very quiet and at full speed is not audible over the system fans.

I am only briefly going to cover the actual process to overclock your card as there are numerous guides on how to do this and there are always people willing to help you here on AOA..

Basically overclocking your card involves either installing coolbits.reg which is available here on AOA, or using modified drives such as those from Tweaks 'r Us which have this feature pre-enabled and then enabling manual overclocking and moving the core slider up 5Mhz at a time, running the “test settings” and when it reaches a point where it fails the test back off around 10MHz and benchmark to ensure stability. Once you have found your optimum core speed then repeat the process with your memory until you have the best overclock attainable.

The core should nearly always be overclocked first as your maximum core clock may not always be achievable when your memory is maxed out, in most cases core speed is more beneficial than memory speed.

In my case I reached 580MHz on the core and 1450MHz on the memory which is a 29% overclock on the core and around 10% on the memory. Any card which allows a core overclock of more than a quarter straight out of the box can't be ignored.

Neither I or AOA take any responsibility for any damage or loss that may be caused through overclocking or modification of your equipment, you perform it at your own risk, however if you experience problems then we are happy to try and help you.

With that aside, let's begin.

The non-standard board design on Palit (and some other) 7900GS cards means that no conductive ink methods are necessary to increase the core voltage to the card, other brands can use modified BIOSes to increase the core voltage to 1.3v in 3D mode, on this card we can change it to suit our needs.

The resistor highlighted in the picture (just adjacent to the power input -Ed) is rated at about 620ohms, reducing the resistance of this will increase the core voltage of the card and hence increase the overclocking potential, what we have to bear in mind is that an increase in voltage is going to cause an increase in heat which the cards heatsink will have to be able to remove quick enough to prevent the card from overheating, artefacting or even failing entirely.

All you need to do to reduce the resistance is to get a sharp pencil and draw a gentle line from one end of the resistor to the other, using a multimeter check after each stoke to see how you are doing, when you reach your desired resistance then you can replace your card and see how much your overclocking potential increases, I recommend aiming to reduce it by 10ohms at a time, this way you can check temperatures each time and not overheat your card.

Through experimentation I discovered that reducing the resistance of the component to 600ohms which is around the 1.3v mark was the optimal level (no major increase in temperature but increased overclocking potential).

This is more than a 36% increase over the stock speed of the card, I discovered that by lowering the resistance to 550ohms (resulting in around 1.45v) I was able to achieve and overclock of 650MHz a staggering 45% overclock, however at this voltage temperature increased quickly and it was only stable for around 60 mins, however if you are willing to mod the heatsink to fit ram-sinks onto the card or to improve ventilation across the rest of the card then it is quite achievable.

It is worth noting that around the 650MHz mark I started to find the overall system was CPU limited so if you have a lower spec CPU than what was used in the test then it may not be worth aiming that high.

I have run a set of benchmarks to highlight the stock performance of the card and how much difference overclocking makes to benchmarking results, these increases can be roughly translated into real-life gaming performance.

The Test System

Athlon 64 3200+ skt939 @2500MHz(watercooled).
MSI K8N Neo4-F.
2048MB Corsair DDR500 3-4-4-8.
2x40GB Barracuda (RAID 0).
Palit 7900GS 256MB.
SB Audigy 2 ZS
Hiper 525W PSU.
Windows XP Home SP2
TRU XG-92.91 Nvidia drivers.

Aquamark 3

A rather old benchmark now but it often useful to help show if a system is being CPU limited and a good comparison for comparing against older cards.

An average of 83,611 at stock speed and 87229 overclocked giving a 4.3% increase.


An older benchmark but still very popular in comparisons with other cards.

An average of 15723 at stock speed and 18426 overclocked giving a 17.2% increase.


A very good benchmark for comparing relative performance at a level that most recent games are running at.

An average of 7283 at stock speed and 8786 overclocked giving a 20.6% increase.


The most up to date benchmark and the newer, better computers come into their own here, cards which are not SM3.0 compliant will fall by the wayside.

An average of 3778 at stock speeds and 4464 overclocked giving an 18.2% increase.

Battlefield 2

To give a better idea of the real-life performance of this card compared to others, I have tested its performance in one of the most popular current games Battlefield 2 by Electronic Arts, the results were taken using FRAPS (a utility to measure current and average framerate during a game) over a period of 5 minutes on Strike at Karkand one of the best maps at a resolution of 1280x1024 with all settings on high except “effects” and 4xAA.

Average Framerates:

Stock: 88.4 FPS
Overclocked: 93.1 FPS

Only a 5% increase in speed, which is not too surprising being that BF2 is capped at 100fps so the points where the card is not under 100% load and would normally go well above 100fps do not influence the results so much, also some CPU limitation may be coming into effect, this is reflected in the Aquamark 3 results previously.

In terms of price:performance ratio this card is untouchable, the 7900GTO comes very close but at less than £120 and with overclocked performance similar to that of a 7900GT the 7900GS has found place in the market that was waiting to be filled and filled it perfectly, as far as I am concerned I cannot find a fault with this card at its current price.

With the performance to keep up with the big guns and the cost and noise level of a much lesser card I think the 7900GS is going to be the leader of the high performance, low cost card arena for some time.

Comments? Discuss in the forums.

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