Testing and overclocking

Today we're looking at a GeForce 8500GT comparison test. The Gainward 8500GT utilizes better GDDR3 memory running at 1,400 MHz, while Zotac sticks to the Nvidia's reference design using GDDR2 memory running at 800MHz. There is quite a difference in speed between these two, and we sincerely doubt that Zotac, with its 100 MHz faster core, will compensate for its 600 MHz slower GDDR2 memory. Whether GDDR3 and its speed play an important role - we'll see soon enough.

The Zotac 8500GT card with 700MHz core speed is much faster than the default 450 MHz of most other 8500GTs.

To refresh the table we incorporated the results of the recently tested Asus EN8600GT card, which runs at Nvidia's default speed of 540/1,400 MHz. We will not discuss this card's results as it's not in the same performance or price range as the GeForce 8500GT cards. If you want to know more about Asus EN8600GT card, you can read the recent review here.

As far as over-clocking goes, Zotac pushed the card almost to its maximum. We still managed to squeeze out an additional 45 MHz from the core, so we reached a final core speed of 745 MHz. The card handled these speeds well, but for maximum stability in Fear and Lost Planet we lowered the frequency to 735 MHz. We mentioned the memory before and we said it runs stable at 1,060 MHz. We over-clocked it to run 130 MHz faster than the default 400 MHz, which is a good result for 2.5 ns memory.

3DMarks

The Zotac 8500GT scored 10,251 which is 945 marks less than the Gainward 8500GT. Almost a thousand marks less for a card with the same chip (running at 100MHz faster) is not a good result, and it is most certainly caused by the weak DDR2 memory.

The core speed helps in Game4 (Nature Test) where Zotac emerges as the winner. Different results in the Composite part of 3DMark are again caused by Zotac’s faster core or Gainward’s greater memory bandwidth. Vertex Shader test resulted in lower performance from Gainward, but that’s because memory doesn’t play a significant role in this test. In Single Texturing and Pixel Shader 2.0 tests memory plays a key role – and GDDR3 memory with greater bandwidth clearly secures a win. Multitexturing test profits from core-speed that draws 64 texture layers on objects as quick as possible.

We can’t compare the Asus 8600GT with the two 8500GT cards because it has 32 Stream Processors, which is twice as many as the 8500GT cards.

By comparing the Zotac 8500GT with Nvidia’s reference card, we see that the over-clocked core brings Zotac to the winner’s spot with a 2,000 mark advantage.

In 3DMark 05 Gainward’s 8500GT card, which uses GDDR3 memory, beats Zotac 8500GT, but only by 162 marks. Single and Multi Texturing tests work on the same principles as the 3DMark 03 tests so the results are similar. The Pixel Shader test should depend on the memory bandwidth, but here we see Zotac’s 12.8GB/s is enough to compete with the Gainward 8500GT. That is not the case in the Vertex Shader Simple/Complex test though, as Gainward thanks to its memory, emerges as the winner.

The Zotac Geforce 8500GT is still significantly ahead of the reference card.