NVIDIA's GeForce 7300 GS
Although ATI launched its budget Radeon X1300-series GPUs with the rest of the X1000 line, NVIDIA waited until nearly six months after introducing its high-end GeForce 7 series to ship a low-end GPU that incorporated that technology. The 7300 GS succeeds NVIDIA's GeForce 6200 series, which stood as the only budget card with Shader Model 3.0 support for some time. NVIDIA's budget part has gained a little weight with the new revision, as least as far as transistors are concerned. The GeForce 7300 GS's G72 graphics chip weighs in at 112 million transistors—nearly 50% more than the 75-million-transistor NV44 graphics chip that powers the 6200 series. Despite this higher transistor count, G72 is actually a much smaller chip. It measures just under 81 mm², while NV44's die size is 110 mm².
The ability to add transistors while shrinking the die size was made possible by NVIDIA's move from 110-nano manufacturing to TSMC's 90-nano fabrication process. In fact, the GeForce 7300 GS was NVIDIA's first discrete graphics product to make the jump to 90-nano; the rest of the GeForce 7 line didn't get its die shrink until a couple of months after the GS hit the market.
The GeForce 7300 GS features four GeForce 7-class pixel shader processors, four texture units, three vertex shaders, and two render back-ends. This isn't the first time NVIDIA has decoupled stages of the graphics pipeline; most of the company's recent GPU designs have favored fewer render back-ends than shader or texture units. Cutting the number of render back-ends reduces the graphics chip's transistor count, and a fragment crossbar is employed to opportunistically feed the render back-ends with pixels from any of the chip's shader units. We've seen the 2:1 pixel shader to render back-end ratio work well with the GeForce 6600 line. However, a relative lack of pixel drawing power could hamper the 7300 GS in older games that don't rely heavily on multitexturing or complex pixel shader effects.
With GeForce 7-class pixel shader processors, the GeForce 7300 GS inherits support for Shader Model 3.0 with 32 bits of floating-point precision per color channel. SLI doesn't make the cut, but it's an unlikely feature to be missed at this price point. The GeForce 7300 GS's support for NVIDIA's PureVideo video acceleration features is far more important, especially since budget graphics cards often find their way into home theater PCs.
One feature that did make the cut in the G72 GPU was antialiasing. NVIDIA's past budget GPUs have sacrificed antialiasing performance in order to save die area, but not so here. The GeForce 7300 GS supports the same AA modes as the rest of the GeForce 7 lineup, without chopped-down blending units or the like. The one exception: the 7300 GS can't do gamma-adjusted blends like the higher end parts.
The 7300 GS's path to local memory is, at maximum, only 64 bits wide. For additional bandwidth and memory capacity, the 7300 GS can leverage NVIDIA's TurboCache technology to access system memory over PCI Express. TurboCache looks at a card's onboard video memory and the total system memory available to determine how much effective video memory to present to the operating system. This effective video memory is the sum of the card's onboard memory and what's been allocated from system memory. Below is a table detailing how much effective video memory the GeForce 7300 GS will have based on different system and graphics card memory configurations.
|System memory||Onboard video memory||Effective video memory|
The MSI GeForce 7300 GS we used for testing features 256MB of onboard memory, so in systems with 1GB or more of available memory, TurboCache presents the card as a 512MB part. That may seem a little excessive for a low-end product, especially since the 7300 GS doesn't have the pixel-pushing horsepower to run at the high resolutions and details levels necessary to stress even 256MB of onboard memory.
One would think there'd be some consistency in GeForce 7300 GS clock speeds among cards from different manufacturers, but that's not the case. Thumbing through what's available from various online retailers reveals cards clocked at 400 or 550 MHz core, with memory running at an effective 533 or 810 MHz. When NVIDIA launched the 7300 GS, it targeted 550 MHz core and effective 800 MHz clock speeds, so we'll be sticking to a card that closely adheres to those speeds. Our MSI GeForce 7300 GS matches NVIDIA's expected 550 MHz core clock and nudges the memory up a smidgen to an effective 810 MHz.
With clock speeds at the high end of the spectrum and 256MB of onboard memory, the MSI card is one of the more expensive 7300 GS cards on the market. It's hard to call a card selling for around $70 all that expensive, but we should note that other manufacturers are hawking GeForce 7300 GS products for as little as $60.
We don't expect much from budget graphics cards when it comes to fancy cooling or indulgent extras, and the MSI's 7300 GS meets our expectations. MSI doesn't bundle the card with many extras. Like the Radeon X1300 Pro, the MSI 7300 GS relies on a generic active cooler that lacks load or temperature-dependent fan speed control. We were also disappointed with its analog VGA signal quality. At resolutions above 1024x768, the card's 2D image quality was noticeably less crisp than that of the other budget cards we tested. I suspect the ribbon cable that connects the VGA output port to the card may be the culprit, and unfortunately, many GeForce 7300 GS cards use a similar design.