Summary: While the GeForce 7800 GTX was only introduced a few weeks ago, retail boards can already be found on store shelves. In today's review we're taking a look at one of the first boards to hit the market, EVGA's e-GeForce 7800 GTX. EVGA takes a regular GeForce 7800 GTX with dual DVI and HDTV output with VIVO support and spices things up a bit by overclocking the board's graphics core by default. See how much faster the board runs as a result in this review!
Although this GPU wasn’t initially in NVIDIA’s playbook for the GeForce 6800 family, it ultimately captured the hearts and minds of many consumers looking to upgrade. The card’s excellent feature set, high clock speeds (the GeForce 6800 GT’s core was only clocked 50MHz lower than GeForce 6800 Ultra), and aggressive pricing made it a tempting upgrade for gamers looking to get the most bang for the buck. Even if they couldn’t afford it, it was the card many NVIDIA enthusiasts aspired to one day own. In many ways, NVIDIA recaptured the spirit of their highly successful GeForce4 Ti 4200 with the GeForce 6800 GT. This DX8 card can still be found in many gamer’s systems to this day.
NVIDIA’s superlative execution continued into the summer and fall with the GeForce 6600 and GeForce 6200 series of GPUs. The GeForce 6600 GT delivered performance greater than the first generation of high-end $500 DX9 cards (the RADEON 9800 XT/9700 series) for a fraction of the price, bringing new levels of performance to the mainstream segment, while the 6200 brought shader model 3.0 to the value market. GeForce 6200 TurboCache cards for example can be found for well under $100.
Meanwhile, on the platform side, NVIDIA introduced nForce4 SLI. The concept is simple: combine two graphics cards together to get nearly double the performance. While SLI got off to a somewhat slow start at the end of 2004, with only a few motherboard partners onboard and only a few dozen titles supported, the technology has rapidly taken off since then. Now nForce4 SLI motherboards can be found from multiple manufacturers and at price points below $150, while NVIDIA claims SLI support for roughly 80 titles, with more on the way. It was largely thanks to SLI that NVIDIA was able to weather the storm when ATI announced their R480 and R430-based VPUs, such as the RADEON X850 XT Platinum Edition and RADEON X800 XL: while a single GeForce 6800 Ultra was generally outgunned by the RADEON X850 XT PE (with a few notable exceptions such as DOOM 3 and Chronicles of Riddick) the X850 XT PE was no match for two GeForce 6800 GTs or 6800 Ultras running in SLI mode.
The only real hiccup NVIDIA encountered last year was PureVideo. This feature ultimately never found its way into the GeForce 6800 family, running best on the GeForce 6600 instead.
Now NVIDIA’s introducing their next-generation part, GeForce 7. The first GPU based on this technology is the GeForce 7800 GTX. And for the first time that we can remember in quite some time, retail cards were available at launch, EVGA was the first company to send us one of their boards for review, and guess what – it runs even faster than the 7800 GTX reference board we tested a few week ago!
Based on this, NVIDIA doubled the number of multiply-add instructions in each pixel pipe for GeForce 7800 GTX, increasing throughput for the pixel shader. On the vertex side, NVIDIA has tweaked the vertex shader units so that they can now process MADD operations in a single clock cycle. The vertex units were also enhanced to speed up geometry processing. For instance, triangle setup is over 30% faster. This shortens the time required to setup complex geometry processing, improving the throughput of the 3D engine. According to NVIDIA, the enhancements they’ve integrated into GeForce 7800 GTX increase pipeline efficiency by 50% on a clock-for-clock basis.
In addition to these tweaks, NVIDIA has also increased the number of pixel and vertex shaders. For GeForce 7800 GTX, NVIDIA has incorporated 24 pixel pipelines, eight more than the 16 pixel pipes found in GeForce 6800 Ultra. Like the GeForce 6800 Ultra, the 7800 GTX’s pipelines are arranged into quads, with each quad consisting of 4 pixel pipelines. The GeForce 7800 GTX consists of six quads (versus four in GeForce 6800 Ultra).
For vertex processing, NVIDIA increased the vertex unit count by two, with the GeForce 7800 GTX consisting of eight vertex shaders versus six in GeForce 6800 Ultra.
NVIDIA incorporated enhancements into more than just the pixel and vertex shaders. In order to improve texture performance, NVIDIA has improved texture fetching, allowing the graphics core to grab and access textures faster. Other improvements NVIDIA has incorporated include a 30%+ reduction in cycle time latencies in the fixed-function setup stages, and similarly cut cycles in gamma adjusted rotated grid AA. The 7800 GTX’s memory controller is more efficient too thanks to improved compression.
In case all those enhancements aren’t enough, NVIDIA has also slightly increased the 7800 GTX’s clock speeds. NVIDIA’s reference specifications for the 7800 GTX call for a 430MHz graphics core (although we’ll delve into this more on the next page), and 600MHz memory. This is an improvement of 30MHz on the graphics core over the original 6800 Ultra’s specs, and 50MHz on the memory.
Reference board design
Like previous high-end launches (such as the GeForce 6800 Ultra last year), NVIDIA is keeping tight control over their board partners for GeForce 7800 GTX. Right now NVIDIA is handling all 7800 GTX board production; NVIDIA’s board partners merely purchase the completed cards from NVIDIA, slap their sticker on the card’s fan, and bundle the card with their promotional material and packaging. This is pretty much as close to purchasing the board directly from NVIDIA as it gets.
By handling all the early production themselves, this allows NVIDIA to ensure that a certain minimum level of board quality is met. In the past, some board partners have skimped on some board components in order to reduce manufacturing costs. Another added benefit for NVIDIA is that supply can be tightly controlled, as they’re manufacturing the cards themselves rather than their board partners. This helps NVIDIA and their board partners bring their products to market quicker, and likely played a key role in the 7800 GTX’s successful availability so soon after the GPU’s official launch.
EVGA makes one key modification to NVIDIA’s reference specs however: for their e-GeForce 7800 GTX card, they’ve decided to clock the graphics core 20MHz higher than default, up to 450MHz when running in 3D mode (the e-GeForce 7800 GTX still runs at 275MHz in 2D mode). Graphics memory speed remains unchanged, at 600MHz, as that’s the speed that the board’s 1.6ns Samsung memory modules are officially rated for. FYI, these are the same memory modules used for GeForce 6800 Ultra a year ago.
EVGA provides two different SKUs for the GeForce 7800 GTX. A limited edition SKU which includes a copy of EA/DICE’s popular online shooter, Battlefield 2 on DVD-ROM, the e-GeForce 7800 GTX Battlefield 2 Edition (Part Number 256-P2-N538-AX), and a second SKU which doesn’t, the e-GeForce 7800 GTX (Part Number 256-P2-N528-AX). The Battlefield 2 SKU retails for a little bit more than the vanilla 7800 GTX card, carrying an MSRP of $619.99 versus $599.99, but well worth it when you factor in the cost of Battlefield 2, which sells for $49.99 at most stores. EVGA also produces a third SKU (Part number 256-P2-N525-AX) that ships at stock clock speeds.
We received the vanilla e-GeForce 7800 GTX SKU for our testing.
Also included in the card’s packaging is a VIVO box with integrated component outputs for hooking the e-GeForce 7800 GTX up to an HDTV, two DVI adapters, a PCI-E power adapter, and an S-Video cable. EVGA also includes a small manual and two case stickers inside the box. Finally, software included with the e-GeForce 7800 GTX is a copy of CyberLink’s PowerDirector 2.55.
As Guru3D discovered earlier this month, the GeForce 7800 GTX’s clocks are slightly more complicated than originally thought. Apparently NVIDIA clocks certain parts of the graphics core at different clock speeds. It appears that the graphics core and pixel clocks are the same (450MHz for the EVGA card, 430MHz for reference 7800 GTX boards), but the geometry clock runs approximately 40MHz higher, 490MHz in the case of our EVGA card. This would be similar to the techniques AMD and Intel use in their latest processors, where different parts of the processor run at frequencies higher than the core clock speed (remember Intel’s “double-pumped” integer ALUs from the original P4 launch?).
It’s unclear which portion(s) of the chip “geometry clock” refers to, the most natural example you may assume would be the vertex units. With only 8 units, it’s possible that NVIDIA can clock these a little higher than the pixel shading engine without affecting yields too badly, or “geometry clock” could refer to an entirely different portion of the graphics core. If NVIDIA were to provide more information on the 7800 GTX’s clocks, overclockers could really go to town tweaking their card’s performance. Could you imagine being able to adjust three or four different clocks in your 7800 GTX card? In applications where you’re more vertex-bound, you could bump up the vertex engine’s clock more, or perhaps you could overclock your pixel shaders just a little bit more for added performance.
One last thing we should note, this 40MHz clock speed bump still applies if you manually overclock your graphics card. For instance, we were able to overclock our e-GeForce 7800 GTX up to 489MHz on the core, as a result, RivaTuner monitored the card running at 529MHz.
Pacific Fighters - OpenGL
Far Cry – Direct3D
IL-2: FB – OpenGL
LOMAC – Direct3D
DOOM 3 – OpenGL
Half-Life 2 – Direct3D
Battlefield 2 – Direct3D
DOOM 3 – OpenGL
Half-Life 2 – Direct3D
GeForce 7800 GTX core: The GeForce 7800 GTX (formerly codenamed G70) is NVIDIA’s fastest graphics processor to date. NVIDIA has increased the number of pixel and vertex shaders, up to 24 (from 16 in GeForce 6800 Ultra) and 8 (versus six in the 6800 Ultra) respectively. NVIDIA has also incorporated improvements in each of these units to speed up processing time, as well as improve the chip’s ability to handle floating-point math, which is used increasingly more often in today’s shader-heavy games. NVIDIA has also improved the 7800 GTX’s ability to fetch textures. In addition, NVIDIA has bumped up the clock speeds, up to 430MHz on the core, and 600MHz for the memory.
Price: At $600, the e-GeForce 7800 GTX certainly isn’t cheap, and it’s going to need a fast processor for best performance. Gamers on a budget will have to look elsewhere (or save for awhile).
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