There have been lots of questions about why we chose to do our Part 2 article using the 3.7 Cats from ATI rather than waiting until today to use the brand new 3.8 version of the drivers. Our reasoning behind this decision was two fold: we wanted to get yesterday's article out as a timely follow-up to last weeks Part 1 of the series, and we also wanted to do a comparison between the 3.7 Cats and the new drivers.

With the Radeon XT series, ATI introduced a new feature called OverDrive. The basic principle of OverDrive is that the GPU can run at higher clock speeds if it is running cool enough, so as long as the chip is cool enough it will safely overclock. ATI’s OverDrive technology uses a combination of a hardware thermal diode and software support to keep track of the temperature of the GPU. If the temperature is within certain predefined limits, the drivers will increase the GPU clock speed by a safe margin defined by ATI. Once the GPU heats up again to the point where ATI can’t guarantee no degradation of chip-life, the drivers will underclock the GPU to as low as its original clock speed (but never lower). The Catalyst 3.8 drivers enable support for the thermal diode present on the Radeon 9800XT and the Radeon 9600XT; note that none of the previous Radeon cards have the thermal diode and thus will not support OverDrive.

The whole idea that a reputable company would be building any kind of overclockability into their product has really intrigued us. We had lots of questions like: how much will performance improve, and will stability be an issue. How much can we really get for nothing? Well, the answers may surprise, but even if they don't, there are some very interesting implications from the way things have played out. But before we get to that, we are going to take a look at the new interface, and then go through all the games in the list one more time.

This time for our testing, we will only be doing 1600x1200 with AA/AF on and off for games that have the option. All of our graphs will use the data we collected for Part 2 and compare it to what we found after we received our drivers from ATI yesterday. It’s been a long night, but it was well worth it.

We used the same benchmarks on the same FX51 system as in Part 2. Let’s let the show begin...

Catalyst 3.8 Drivers
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  • Anonymous User - Thursday, October 09, 2003 - link

    so... 50 and 51 ... do you play your games for 10 minutes, then turn off the computer to let it cool down so you can get better fps? hell no. you play and play and play till yer done.

    doing all these benchmarks without letting the card cool down (whether it shows the 3.8 full potential or not) is more like what users will experience on their systems. That makes this data more useful to me than anything else they could have done.

    crazy ati fanbois

    Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    I'm with 50. He is right. Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    trying to test a temp related mod without controlling temp in the case is just assinine. This proves absolutely nothing. They themselves said they did not allow cooling between tests so they don't know how the overdrive was working. I would be more impressed with just the change in speed numbers than the fps. That would at least tell us whether the overclocking was used throughout the test and not shut off after the card got hot on the 2nd benchmark. The test had no control basis and therefore all the data is trash. Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    when the 9600 XT is going to be realased, i'm waiting for it Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    In your discussion of image quality, I don't see
    a comment on HALO. Yet on my PC (P4C 2.8,
    Radeon 9800 PRO, Catalyst 3.6) I get clear drawing
    errors. Looking at the sky in any outdoor scene in
    level 5 or 8, it shows just a gaping hole which
    should've been obscured by fog. More subjectively,
    the fog in the swamps at the start/end of level 6
    also doesn't work as well as on the XBOX.

    What are the experiences of people with different
    hardware/drivers?
    Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    I dont see the overdrive tab, is this only visible with 9800pro etc.
    My card is a 9500pro!!
    Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    ... so they will only allow the Mhz, where every card works? Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    maybe we are gonna see unofficial moded versions of these drivers, with the overclocking limit removed :d . ATI just cant allow this difference between the users cards, when one has a "overclocker" card and gets his 10% and the other has something "allergic to speed" card lol and gets nothing. ATI just cant make the speed of the card luck Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    I'm disappointed that Anand didn't try to find out why overdrive didn't produce better figures.

    Overdrive might not overclock as much as some people want, but it should still give more impact than just 0,5fps.
    Since the 9800XT is mainly an overclocked 9800Pro we should be able to accurately estimate the impact of overdrive on the 9800XT.

    I suspect that we would get far better numbers if Anand had used 1024*768 instead of 1600*1200 4xAA.
    Afaik overdrive only overclocks the GPU and not the memory. At 1600*1200 you are more likely to run into a memory bandwith limited situation. (Especially with all those DX8 games)
    In such a situation it is logical that overdrive won't give any large increase in fps.

    The other explanation is that the air termperatuur in the computer case Anand uses was very high and therefor overdrive was not able to overclock much.

    In either case it is a shame that Anandtech didn't do anything at all to discover where the disappointing results came from.
    (I hope nobody here actually thinks that ATI would go through the trouble of creating overdrive when it would only gain 0,5 fps)
    Reply
  • Anonymous User - Thursday, October 09, 2003 - link

    this is getting way too geeky... Anand, you are indeed the master geek. I mean in this in a good way... or am I? hahaha hust kidding. You guys sure have a lot of patience. Incredible! Reply

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