Contrary to the RADEON 9800 PRO DDR-II, the PCB of the GeXcube RADEON 9800 XT carries only eight DDR memory chips, but the capacity of each chip is 256MB rather than 128MB. So, we have a total of 256MB of graphics memory. The chips come from Hynix, work at 365MHz (730MHz DDR) and have 2.5ns access time. Alas, the relatively simple PCB design doesn’t allow the memory to be clocked at its nominal, 400MHz (800MHz DDR). The VPU works at 412MHz, but when you enable ATI’s OVERDRIVE technology the frequency may vary from 412 to 432MHz depending on the temperature as measured from the core-integrated thermal diode. If you want precise numbers: 432MHz is set when the temperature is below 52oC, the frequency goes down to 418MHz after the temperature rises and gets back to the nominal when the temperature is 62oC. You shouldn’t foster any hopes about any performance gain from OVERDRIVE, as it is highly improbable that the complex chip, the R360 is, will be less than 52oC hot under a workload.
Noise, Overclocking and 2D Quality
This time the engineering team from ATI Technologies did a nice piece of work developing the cooling system. First of all, it has become practically noiseless. There’s a reservation, though. It is noiseless when the GPU temperature is below the critical mark, otherwise the cooling system increases the rotational speed of the fan. However, the noise, or rather rustle, is quite bearable even in the worst case. You may only find it unacceptable if you’ve got a quiet system, with fewer fans.
As for the operational temperatures, they are quite normal, save for the memory chips on the backside of the PCB. Under high workloads, the plate covering the chips heats up to 55-56oC. I guess a bigger size of the plate or some additional ribs would be of help.
2D quality was up to the mark in all resolutions up to 1600x1200@85Hz. Overclocking added some pleasant emotions: the core worked at 452MHz. When the frequency was increased further, 3DMark03 yielded some artifacts: places of the image where pixel shaders were used became all covered with white dots. The memory stopped short of the nominal 400MHz (800MHz DDR) frequency, notching 390MHz (780MHz DDR). Again, there were visual artifacts at further memory overclocking. 452MHz is good enough a result for so complex a GPU manufactured by a not-very-thin tech process. The memory overclocking evidently was limited by the relative simplicity of the PCB – it is not intended to clock the memory so high.
Taking the GeXcube RADEON 9800 XT at large, I’m all positive about it. It is free from obvious flaws, although the cooling of the memory chips on the backside of the PCB might be better. The accessories are not exuberant, too, but that’s not really a requirement for a card without VIVO functionality. So, if you are looking for a high-performance and quiet graphics card, the GeXcube RADEON 9800 XT may suit you.