Overclocking and Noise
Overclocking
At the top of page two I alluded to the fact that PoV's 5900XT wasn't based on NV35. While technically it should be, the overclocking results say different.I've reviewed the NVIDIA 5950 Ultra reference board and retail 5950U examples from AOpen and ASUS, along with a couple of test samples of Gainward's watercooled CoolFX 5950 Ultra boards and finally a recent aircooled Gainward 5950 Ultra. Being based on NV38, an NV35 respin that gave the core new found overclocking heights, all six of the NV38-based boards that I've tested were capable of at least 530MHz core frequency, with the second Gainward CoolFX hitting over 600MHz.
Bearing that in mind, NV35 owners will testify to that core's inability to do much more than 500MHz. So with 5900XT being an NV35 at heart, speed binned to identify it as a lower clocking NV35 example, it was a bit strange to see the Point of View do this.
A full 170MHz core overclock and well over the default core frequency of 5950 Ultra means that either some 5900XT's are using premium NV38 cores due to supply and demand, or Point of View are selectively choosing the cores they purchase from NVIDIA. The first option seems the most likely. With 5900XT being a much bigger seller than 5950 Ultra, it's possible that some NV38 cores are being used to sell 'NV35' products.
Or I have a freak sample. Of course your mileage will definitely vary, but it's something to definitely keep in mind.
With the Hynix 2.8ns DRAMs being rated to 714MHz DDR, it was no surprise to see the memory frequency limited to 775MHz, 75MHz over the shipping clocks. Other 5900XT reviews point to similar memory overclocks, so Point of View aren't doing anything different in that respect.
560MHz core frequency means 2240Mpixels/sec of pixel fillrate and 4480Mtexels/sec of multitexture fillrate. 775MHz means 24.8GB/sec of memory bandwidth.
43% extra core speed will help in DX9 titles where the shader units are working hard, giving the DX9-deficient architecture a welcome boost.
That said, other 5900XT reviews point to simple overclocks around the 450MHz mark. Indeed, Gainward's 'Golden Sample' 5900XT sets the core clock to 450MHz when using ExpertTool, their in-house overclocking utility.
