Summary: AGP users rejoice as today NVIDIA's finally releasing the GeForce 7800 GS AGP! Based on the highly regarded G70 GPU, the 7800 GS brings a number of new features to the table, and as you'll see in our article, is a terrific overclocker. See how it stacks up to the GeForce 6800 Ultra/GT, 6600 GT, as well as a number of other GPUs in this article!
The following is a quote from a petition started by Leon Roy on petitiononline.com:
For all of you who have begged, pleaded, and petitioned NVIDIA and their board partners to release a GeForce 7800 AGP graphics card, our review today of BFG’s GeForce 7800 GS OC AGP must provide a sense of redemption: finally you’ve won! As today NVIDIA’s officially announcing the GeForce 7800 GS AGP, and like previous GeForce 7800 launches, today’s announcement is a hard launch, meaning you can go out today and buy a GeForce 7800 GS AGP card at your local retailer, e-tailers should have their respective GeForce 7800 GS cards online for sale by next Monday, February 6th.
As its name implies the GeForce 7800 GS AGP is based on the exact same architecture as the GeForce 7800 GTX that was first launched in June 2005. This means that you’ve not only got NVIDIA’s CineFX 4.0 architecture with its more robust pixel and vertex shading units and support for transparency anti-aliasing, but also NVIDIA’s PureVideo technology. GeForce 6800, 6800 GT, and 6800 Ultra cards based on NVIDIA’s NV40 GPU didn’t provide support for PureVideo.
The GeForce 7800 GS isn’t exactly a direct AGP translation of the GeForce 7800 GT/GTX however. NVIDIA’s made a couple of key changes that will ensure that the GeForce 7800 GT and 7800 GTX remain at the top of the heap in their lineup when it comes to performance. Let’s see what has changed with this new GPU.
While NVIDIA has integrated the same G70 graphics core that has been used for the GeForce 7800 GTX and GeForce 7800 GT in the past into the GeForce 7800 GS AGP, a number of internal changes have been made to the GPU. The following chart summarizes what’s new with NVIDIA’s latest spin on the G70 GPU:
In addition to trimming the number of functional units, NVIDIA also reduces the clock speeds on the GeForce 7800 GS AGP, as the graphics core runs at 375MHz, that’s 25MHz slower than the GeForce 7800 GT and GeForce 6800 Ultra, and 25MHz faster than the GeForce 6800 GT. Paired alongside the graphics core is 256MB of GDDR3 memory running at 600MHz (1.2GHz effective), this is the same speed as the GeForce 7800 GTX, and 50MHz faster than the GeForce 6800 Ultra. This should allow it to perform well at high resolutions, particularly once AA/AF is applied.
The end result of all these changes is a part that looks on paper to resemble the GeForce 6800 GT/Ultra family more so than the GeForce 7800 line. For instance, the 7800 GS has just as many pixel pipes as the GeForce 6800 Ultra/GT, and is clocked right in the middle of the two GPUs at 375MHz. It also has the same number of texture address units and vertex units as the high-end GeForce 6800 cards do. NVIDIA further cripples the GeForce 7800 GS AGP by disabling half of its ROPs, although in all honesty this probably isn’t as significant as the aforementioned changes. The only area that really didn’t see any reductions is the memory subsystem, which is essentially unchanged from the GeForce 7800 GTX 256MB.
Of course, this line of thinking is all based on paper specs. By now you all should know that NVIDIA’s incorporated a number of changes into the GeForce 7 line that should improve performance on a clock-for-clock basis. The 7800’s vertex shaders have been tuned to speed up geometry processing (for instance, triangle setup is over 30% faster), while the pixel and vertex units that have been tweaked to perform better at handling MADD math operations, which are frequently used in lighting and normal map calculations (among others) in many of today’s latest titles. NVIDIA has also tweaked the GeForce 7800s to scale better at mega-high resolutions like 2048x1536.
Since the 7800 GT and 7800 GTX were so drastically different than preceding GeForce 6800 parts, we never got a chance to test these improvements – we literally couldn’t disable the necessary pixel and shading units to run true apples-to-apples comparisons. But since NVIDIA’s done all of the work for us by disabling these units in the GeForce 7800 GS AGP, we can now finally get a better idea of how the two architectures compare. Keep in mind that this still isn’t a completely accurate comparison, as the 7800 GS AGP has fewer ROPs than the 6800s, but this is the closest we’ve ever gotten to being able to run a direct comparison. We’ll start with 3DMark first.
3DMark 06– Direct3D
HL2: Lost Coast
Our line of thinking when asking this question was that while we understand the improvements NVIDIA has incorporated into GeForce 7800, as well as new features such as transparency AA and PureVideo (which didn’t work on high-end 6800 cards), the average consumer probably doesn’t. And while it’s true that GeForce 6800 Ultra and 6800 GT are incredibly difficult to find on store shelves in AGP form nowadays, NVIDIA’s board partners have been quietly producing GeForce 6800 GS AGP cards for about a month now. These 6800 GS AGP cards are by no means the GeForce 6800 GT killer that the GeForce 6800 GS on PCI Express interface is, as they’re clocked considerably lower – NVIDIA’s reference specs call for a 350MHz graphics core (versus 425MHz for the PCI-E card) – but they also sell for considerably less than the GeForce 7800 GS AGP’s $350 MSRP. Street prices on cards range from about $190 all the way up to $220.
That’s over $100 less than the GeForce 7800 GS AGP.
NVIDIA’s response to our question was that when determining the feature set for GeForce 7800 GS AGP, they had specific goals in mind, particularly when it comes to power. NVIDIA feels that AGP systems have a different power budget than PCI Express systems. Because of this, they focused on delivering a part that could not only deliver the best price/performance ratio possible, but do so at a particular price point while at the same time doing so without consuming an excessive amount of power so they could get the card in as wide a range of AGP systems as possible.
When you consider that the GeForce 6800 Ultra AGP required a dual-slot cooler and two Molex power connectors in order to run at full speeds, this answer is certainly reasonable. After all, the PCI Express interface natively provides more power than AGP, and considering that the GeForce 7800 GTX draws up to 100W of peak power consumption and that most AGP owners probably wouldn’t want to upgrade their system’s power supply at this point anyway just to run a new graphics card, NVIDIA’s argument does sound plausible. As a result of the reductions, the GeForce 7800 GS AGP boasts a peak power consumption of only 75W (10W lower than the GeForce 7800 GT).
And while they didn’t tell us this directly, another aspect we should mention is that NVIDIA’s allowing their board partners to crank up the clocks on their shipping cards. The BFG GeForce 7800 GS AGP card we’re reviewing today is a perfect example of this. So users who may be a little disappointed by the stock NVIDIA clocks should look closely into the shipping retail boards from NVIDIA’s board partners. Like the GeForce 7800 GT and 7800 GTX, partner boards will be shipping at much more extreme clock speeds in the coming weeks.
While some enthusiasts may be a little disappointed with NVIDIA’s reference clock speeds for the GeForce 7800 GS AGP, they’ll be glad to hear that the BFG GeForce 7800 GS OC AGP runs at speeds faster than NVIDIA’s reference specifications call for.
BFG starts by clocking the graphics core at 400MHz. This is 25MHz over NVIDIA’s default clock frequency of 375MHz, and brings the GeForce 7800 GS AGP up to par with the GeForce 6800 Ultra in fill-rate at 6.4 Gigatexels/second, an improvement of 6%.
In addition to overclocking the graphics core, BFG also overclocks the memory on their GeForce 7800 GS OC AGP card. Whereas NVIDIA’s reference speeds call for 600MHz memory (1.2GHz effective), BFG runs the memory modules on their 7800 GS OC AGP at 625MHz (1.25GHz effective). As a result of this change, peak memory bandwidth is improved by 4% from 38.4GB/sec on the stock GeForce 7800 GS AGP to an even 40.0GB/sec on BFG’s GeForce 7800 GS OC AGP.
The only other significant deviation that we can see from BFG’s GeForce 7800 GS OC AGP and NVIDIA’s reference GeForce 7800 GS AGP card is the PCB itself. BFG uses a blue PCB while NVIDIA sticks to the more traditional green for the PCB on their reference board. BFG also places a speaker just behind the VGA connector on their GeForce 7800 GS OC AGP card. Based on the pictures provided by NVIDIA of their GeForce 7800 GS reference board, this is another difference between the two boards, but it’s certainly possible that this was added to shipping retail cards at the last minute to warn end users if their card begins to overheat (the speaker will also squeal loudly if you forget to plug in the card to your system’s power supply).
Speaking of overheating, we don’t think this will be much of a problem for the GeForce 7800 GS. During our testing, we never saw the card approach its threshold temperature of 115°C. The card idled at 46°C with a peak load temperature of 67°C in our open-air testing environment.
Like previous GeForce cards, the 7800 GS AGP runs in two different modes, a 3D mode where the board runs at its full clock speeds, and a 2D mode, where the graphics core runs at 275MHz while the memory continues to run at full speed. We give a big thumbs-up to the new cooling unit NVIDIA has integrated onto the GeForce 7800 GS AGP. It’s basically a miniaturized version of the GeForce 7800 GTX’s cooler. Cool air is ducted from the card’s fan across the GPU and nearby memory modules, and then shoots out the right side of the card, just below the external power connector. The fan on the BFG card runs quieter than the GeForce 7800 GTX 256MB fan (it’s quieter than the GeForce 6800 GT/Ultra too for that matter) and varies its RPMs based on the GPU’s current temperature. Even in its loudest mode though it’s nowhere close to approaching the noise levels of the GeForce 6800 Ultra, we were actually surprised just how rarely the RPMs had to crank up. Other than while we were overclocking and a few moments here and there, the fan never really cranked up to its full speed setting.
Hardware accessories bundled with the BFG GeForce 7800 GS OC AGP include a power adapter and DVI adapter. Software included with the card is limited to a copy of NVDVD 2.0 and BFG’s Gamer’s Toolkit CD, which includes a copy of GameDrive 9.0 (useful if you want to play games without having to keep the game’s CD in your disc drive), and trial copies of System Mechanic Pro 5, Spy Sweeper, Window Washer and Desktop Firewall from Webroot Software. BFG also includes a couple of case badges for your PC’s case.
3DMark 06– Direct3D
3DMark 06– Direct3D
Half-Life 2 – Direct3D
Battlefield 2 – Direct3D
Quake 4 – OpenGL
IL-2: FB – OpenGL
F.E.A.R. – Direct3D
Call of Duty 2 – Direct3D
Serious Sam 2 – Direct3D
Far Cry – Direct3D
HL2 Lost Coast
HL2 Lost Coast
GeForce 7800 GS core: While NVIDIA isn’t giving us a replica of the GeForce 7800 GTX in AGP form with the GeForce 7800 GS, with GeForce 7’s more powerful shaders, transparency AA, and PureVideo support, the GeForce 7800 GS AGP brings along just enough features to make it a tempting solution for many AGP users. And did you check out those HDR results with Far Cry? If that’s any indication of what the GeForce 7800 GS AGP can do with next-gen titles that also use FP blends for HDR, then the future for the GeForce 7800 GS AGP looks bright indeed.
Too many reductions?: Critics would probably argue that NVIDIA’s made too many compromises with the GeForce 7800 GS AGP. We can see it now: only 16 pipelines with 6 vertex shaders? Only 375MHz on the graphics core (keep in mind that the BFG card we’re reviewing is clocked at 400MHz)?