GeForce Go 7900 GTX: For Hardcore Gamers on the Go

GeForce Go 7900 GTX: For Hardcore Gamers on the Go

COMPANY: Dell, Inc. April 17, 2006

SPEC DATA

Price: £2,125.00 Direct
Type: Gaming, Media
Operating System: MS Windows XP Media Center
Processor Name: Intel Core Duo T2600
Processor Speed: 2.16 GHz
RAM: 2048 MB
Hard Drive Capacity: 100 GB
Graphics: nVidia GeForce Go 7900GTX
Primary Optical Drive: DVD+R DL
Wireless: 802.11a/g
Screen Size: 17 inches
Screen Size Type: widescreen
System Weight: 8.8 lbs

High-end laptop PCs for gamers are getting lighter, though they're still the behemoths of the mobile PC world. The original Dell XPS notebook weighed 9.25 pounds, was a full 2 inches thick and had a relatively puny 15.4-inch screen. The new Dell XPS M1710 weighs 8.8 pounds and has a 17-inch display. With power bricks, the difference becomes 11.4 lbs versus 10.6 pounds; the new power brick is a tad lighter, though it's all relative. It's progress, of sorts. The high-end version of the M1710 now ships with Nvidia's new GeForce Go 7900 GTX. Pretty much the same GPU as the desktop 7900 GTX, the mobile version is simply clocked lower and packaged differently.
We're going to focus on the Nvidia's new mobile GPU; check out PC Magazine's XPS M1710 review for more details on the new Dell laptop itself.
Dell positions the XPS M1710 as a mobile desktop replacement for gamers. Instead of lugging along that tricked out aluminum tower with the transparent side panels and the glowing cold cathode tube lighting, plus monitor, you'll bring along a Dell XPS with it's 17-inch, 1920x1200 display, shiny red exterior and glowing blue LEDs.
Dell isn't the only company shipping the Go 7900 GTX at launch; Toshiba is also launching its Satellite P105, which ships with the new GPU.
Given the positioning as a desktop replacement, how does this new GPU really fare against desktop GPUs? And how does it compare with the past generation of killer laptops?
Nvidia only launched the GeForce Go 7800 GTX last November, a scant six months ago. The fundamental architecture of the 7900 is identical to the 7800. While Nvidia has tuned some of the circuitry, most of the differences lie in the process shrink from 110nm (7800) to 90nm (7900).
On the mobile side, this allows Nvidia to increase the recommended clock rates without increasing power draw. Nvidia is also launching the Go 7900 GS, which is essentially a cut-down version of the 7900 GTX that can fit into a much lower power envelope.
Let's compare the three. Note that the two GTX numbers are from Dell XPS gaming notebooks; the third is an Nvidia suggested spec, but the company notes that manufacturers are free to tinker with clock rates in shipping products.

Model Go 7800 GTX Go 7900 GTX Go 7900 GS

Core clock rate 400MHz 500MHz 375MHz

Memory clock rate 530MHz 600MHz 500MHz

GPU thermal power 40W (estimated) 45W 20W

Pixel shader units 24 24 20

Vertex shader units 8 8 7

Process technology 110nm 90nm 90nm
As you can see, the Nvidia has increased the core and memory clocks in the Go 7900 GTX versus the Go 7800 GTX, while the thermal power has only increased slightly. Continued... We tested the Go 7900 GTX on one of Dell's new XPS M1710 laptop PCs, which features Intel's Core Duo T2600 CPU, clocking at 2.16GHz. Since this is being positioned as a desktop replacement, we ran a desktop system using a PNY Verto 7900 GTX Limited Edition. The desktop system was based on the desktop Core Duo system we built, so the processor, memory and chipset are comparable. However, PNY's limited edition 7900 GTX does run at a core clock of 675MHz and a memory clock of 820MHz. It's not entirely a fair comparison, but given the market segmentation, we think it's worth a look. We also dug up several comparable benchmarks from our GeForce Go 7800 GTX
The benchmark testing consisted of 3DMark06 and four 32-bit games—Half-Life 2, Call of Duty 2, Doom 3 and F.E.A.R. Note that we're using Call of Duty 2 version 1.01, which supports multithreading. Our initial tests show improved performance in dual-core and Hyper-Threaded CPUs. The Half-Life 2 benchmark uses the Lost Coast video stress test.
We were able to compare the results of two games running on the Dell XPS M170, which uses the single-core Pentium M running at 2.13GHz and using the GeForce Go 7800 GTX. Those games are Doom 3 and F.E.A.R., neither of which are optimized for multithreading.
Let's take a look at the results. 3DMark06 is a synthetic test, making heavy use of pixel and vertex shaders in all scenes. The Shader Model 3 tests also use high-dynamic range lighting. We only ran the default 3DMark test. The four games were run at 1280x1024 (or 1280x960 in the case of F.E.A.R.), and 1600x1200, with AA/AF off and on.
First, let's take a look at the results comparing the desktop Core Duo system running the higher clocked Verto 7900 GTX Limited Edition to the Dell XPS M1710:
It's no surprise that the higher-clocked desktop card runs faster. But the Dell XPS M1710 runs quite well in its own right. The numbers at 1280x1024, with AA and AF on, are quite robust, with the exception of Call of Duty 2 which can be quite a performance hog. Similarly, at 1600x1200, performance is also quite good, except for Call of Duty 2. However, we're not sure we'd run CoD2 at 1600x1200 even on the desktop system.
It's surprising just how fast Half-Life 2's Lost Coast video stress runs at all settings, and it's no surprise that Doom 3 runs well at all settings. Even F.E.A.R. runs pretty darned well, and it's a well-known performance killer. Limited subset of our tests are usable for comparison, but let's takes a look at what we have:
Slower core and memory clocks contribute to substantially inferior performance on the GeForce Go 7800 GTX versus the new kid on the block. Note that the Dell XPS M170 uses only a single-core processor, but this probably has little impact on these two games. The overall CPU clock frequency difference between the two notebooks is only 30MHz.
The memory bandwidth, however, is higher on the M1710, so that may be a factor.
Of course, the Go 7900 GTX system was running newer drivers, too, which may also have some impact.
Still, the difference is pretty substantial, so the combination of dual-core CPU, higher bandwidth memory, and a faster GPU is a potent combination, at least in these two games. Nvidia is also touting the video capabilities of the Go 7900, including hardware-assisted decode of H.264 streams. This is really a forward-looking feature, but since two laptops have already been announced with HD-DVD support, including one from HD-DVD leader Toshiba, this feature will certainly come in handy in the future. Nvidia estimates you'd see up to 50% lower CPU utilization using GPU-assisted H.264 decode.
Even with standard WMV-HD content, you'll see some improvement. We ran the Coral Reef 1080p trailer, which is downloadable from Microsoft's Windows Media HD page. Turning on hardware acceleration saw CPU utilization averaging under 25% on just one core. With hardware acceleration off, CPU utilization on one core jumped to about 40%, but we also saw spikes on the second core.
There was one very perceptible difference: With acceleration on, we could run full screen. With hardware acceleration turned off, the video clip would only run in a window. True, the window took up nearly the entire screen, but that's not quite the same as running full screen. So even if you're not running H.264 today, you'll see some improvements with Nvidia's hardware decode.
Note that for DVD playback, you'll need a software DVD player with hardware acceleration. The good news is that you're no longer restricted to Nvidia's PureVideo DVD decoder; the company has worked with CyberLink (PowerDVD) and InterVideo (WinDVD) to improve hardware support for Nvidia GPUs. Since the Go 7900 GTX on the surface just seems like a refresh of the Go 7800 GTX, we weren't expecting substantial improvements in performance over the earlier release. But the fine tuning of the architecture, plus the process shrink, seems to have paid substantial dividends. The GeForce Go 7900 GTX offers substantial improvements in performance over the older GPU, albeit at the cost of slightly increased power consumption.
While it's not a complete replacement for a desktop GPU, the GeForce Go 7900 GTX offers enough performance to keep most gamers happy, even running at high resolutions. We're also intrigued by the idea of a thin and light laptop with the GeForce Go 7900 GS, so we'll keep an eye open for one of those. As technology moves forward, even these huge laptops are getting a bit thinner and a bit lighter, though. If the idea of a big 17-inch, wide screen display is appealing enough to overlook the added bulk, then systems with the GeForce Go 7900 GTX offer graphics punch to go.

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