Budget 90nm Graphics: NVIDIA GeForce 7300

What's Under the Hood?

As the title of the article implies, the GeForce 7300 is NVIDIA's very first shipping 90nm part. In order to come out with the 7800 series as early as they did, NVIDIA didn't want to try anything tricky like pushing the process envelope and moving to 90nm. Sticking with the 110nm process proved to be a good decision for NVIDIA this time around. With TSMC bringing out their 80nm process and NVIDIA just now starting to manufacture 90nm parts, it will be interesting to see who takes the next step towards smaller transistors. ATI has been pretty aggressive recently, but the 80nm process should be a fairly simple transition (as far as fabrication process transitions go), so it could go either way.

Aside from transistors with 90nm gate lengths and FP16 framebuffer blending, the 7300 will also carry NVIDIA's TurboCache technology. With relatively few vertex shaders, pixel shaders, and render outputs, a little die area can afford to be spent on beefing up caches to allow for the efficient use of higher latency system memory. This allows NVIDIA to "support" games that require more RAM than is physically present on the card. With the GeForce 7300 sporting 128MB of RAM, TurboCache allows games to treat the graphics subsystem like it has 256MB of RAM. Likewise, the 256MB version of the 7300 will look like it has a 512MB framebuffer to software.

In addition to allowing programs that require more graphics memory to run efficiently, NVIDIA is also able to cut the bandwidth to graphics memory down without taking a large performance hit. The bandwidth gained through TurboCache augments the bandwidth of onboard memory and should provide some good speed advantages for low end parts. The 128MB version of the 7300 will have a 64-bit memory bus, which is actually on the high end for TurboCache parts. It is likely that the extra RAM and onboard memory bandwidth boost in this generation of TurboCache parts is there to enable the use of memory intensive HDR features (like the FP16 blend absent from 6200 parts).

The rest of the NV4x/G70 features will also come along with this new budget part without exception. This includes NVIDIA's PureVideo features for clean DVD viewing and efficient playback of HD content, and the possibility of SLI in the future. SLI is not part of the 7300 series at launch, but, if NVIDIA's track record is any indication, we can all but guarantee SLI support. Shader Model 3 is of course supported, but with fewer pipelines, the efficiency of high end features like looping and conditional rendering will not be optimal. We should also see more efficient handling of math intensive shaders due to the 7 series ability to handle more Multiply-Adds per clock than the 6 series. Here's the full breakdown of what the GeForce 7300 brings to the table.

Budget Card Features
	Radeon X1300	GeForce 6200TC	GeForce 7300
Vertex Pipelines	2	3	3
Pixel Pipelines	4	4	4
Render Outputs	4	2	2
Core Clock Speed	450	350	550
Memory Clock Speed	500	350	350
Memory Size	256-512MB	16-64MB	128-256MB
Memory Bandwidth	64-128bit	32-64bit	64bit
GPU Video Decode	yes	yes	yes
FP16 Filter	no	yes	yes
FP16 Blend	yes	no	yes

Clearly, the 7300 will be able to win out over the 6200 TC in any flavor, but we will need to wait until we get our hands on a part to know exactly what flavors of X1300 it will match up against. Listed in our table is our best guess match (the vanilla X1300), but we'll try to test as many flavors as we can when we are able to do a performance comparison.

For now, we can at least take comfort in the fact that a >50% increase in core clock speed, increased memory size and bandwidth, and higher level of architectural efficiency over the 6200 TC will help make the new GeForce 7300 very competitive at a <$100 price point. While it may not get everyone's blood boiling, the 7300 is not just an exciting part for the budget market, but it will help raise the bar for the minimum target that game developers will be shooting for over the next couple of years.