Gigabyte GTS 450 OC2 review
Author: Luka Rakamaric
Date: 18 Oct 2010

After a much criticized Fermi GF100 GPU, NVIDIA launched the GF104 in July. It was a real surprise at it was not just another cut in half GPU, but instead had some of the shortcomings of GF100 fixed. The main news is that the number of TMUs which has gone up in relative terms, to almost the same amount as the high end GTX 480. The other significant news was the introduction of a superscalar architecture, which has now passed on to the GF 106.

The GPU
The GF 106 would usually be GF104 cut in half. While it is true in the number of SMs, NVIDIA didn’t cut the ROPs and memory controllers in half. You will get one GPC with four SMs, which will give you a total of 192 cores. The whole chip still has a 192 bit memory bus with 3 memory controllers and sets of ROPs. However, if you have thought that you will get something extra, we must say that NVIDIA is launching the GTS 450 in the exact configuration as we expected, which is half of GTX 460. So one memory controller and 8 ROPs are disabled, which gets you a 128 bit memory bus and ‘only’ 16 ROPs.

As for the architecture, it remains the same as the GF104. Each SM has a total of 48 cores, which was 32 in GF100. With two dispatch units, in GF100 there was no need for to use superscalar execution. Now there are three groups of cores that have only two dispatchers. In other words, if your next instruction doesn’t depend on the result of the previous one already in execution, you can use all of the available cores. In the worst case scenario, you end up with 128 cores. Unfortunately, as can be seen with ATI cards that has been using a five stage superscalar architecture for a while now, it is clear that more often than not you are closer to the worst case scenario.

GTS 450 uses GDDR5 memory which effectively quadruples memory throughput. The base memory clock is 902 MHz, which when put effectively reaches 3608 MHz.
The GPU clock is 783 MHz, while the shaders are operating at 1566 MHz. These are stock numbers, but most of the manufacturers are offering much higher clocks in addition to the custom PCB and cooler.