The specs

While NVIDIA didn’t launch the GeForce 6600 DDR2 with much fanfare, it’s officially considered the replacement for the GeForce 6600 with DDR1 memory. The new GPU is built on the exact same manufacturing process as its predecessor, TSMC’s 110-nanometer process, and contains 146 million transistors. The core architecture of the GeForce 6600 DDR2 remains unchanged as well. This means that the chip sports eight pixel pipelines with three vertex shaders and a 128-bit memory interface.

The only difference between the GeForce 6600 DDR2 and the original GeForce 6600 launched last year is that the memory subsystem has been slightly tweaked, with the GeForce 6600 DDR2 sporting DDR2 memory rather than the DDR1 memory used on the original GeForce 6600. If you recall, DDR2 was quickly heralded as the replacement to DDR1 by NVIDIA and Samsung way back in the days with the GeForce FX 5800 Ultra due to its high clock speeds and reduced power consumption, but ultimately never really took off as a replacement in desktop graphics memory because early DDR2 memory modules generated an excessive amount of heat. (A perfect example of this would be the ATI RADEON 9800 PRO 256MB, its memory only ran 10MHz faster than its DDR1-based sibling yet the 256MB DDR2 board required heatsinks on its DDR2 memory modules to keep the modules cool. Even with this addition the board’s memory still generated lots of heat.) Because of this, we were eager to see how cool the DDR2 memory modules ran on the GeForce 6600 board, but more on this later.

NVIDIA’s reference specifications call for 256MB of DDR2 running at 400MHz, which is an improvement of 125MHz over the original GeForce 6600’s memory speed of 275MHz, although we wouldn’t be surprised to eventually see some board manufacturers produce 128MB SKUs at even lower price points.

To further improve performance of the GeForce 6600 DDR2, NVIDIA has also bumped up the core clock frequency from 300MHz on the original GeForce 6600 to 350MHz on the newer GeForce 6600 DDR2. This is an improvement of 15%b on the graphics core.

GeForce 6600 Series Comparison
	GeForce 6600 GT	GeForce 6600 DDR2	GeForce 6600	GeForce 6600 LE
Core Clock (MHz)	500	350	300	300
Memory Speed (MHz)	500	400	275	275
Memory Interface Width	128-bit	128-bit	128-bit	128-bit
Memory Type	GDDR3	DDR2	DDR	DDR
Memory Bandwidth (GB/sec)	16	12.8	8.8	8.8
Texel Fill-Rate	4	2.8	2.4	1.2
Vertices/sec	375	262.5	225	225
Pixel Pipes	8	8	8	4
Vertex Pipes	3	3	3	3

With these new clocks, NVIDIA feels they’ve got a pretty strong product on their hands to compete with the X1300 family from ATI. Again, as we mentioned previously the GeForce 6600 DDR2 officially carries an MSRP of $119, but already board partners have announced lower prices for their boards, XFX for example lists the MSRP of the GeForce 6600 DDR2 board we’re reviewing today at $99. The really sweet part is that XFX has clocked their $99 GeForce 6600 DDR2 board at speeds higher than NVIDIA’s reference specifications.