|Massman ||25th May 2009 18:39 |
[WORKLOG] - HD3300 overclocking
First post of the worklog. Here, I will post my most up to date results :-).
: 3DMark01 - 29713
: 3DMark03 - 9038
: 3DMark05 - 7048
: 3DMark06 - 3149
: 3DMark Vantage - 716
: Aquamark - 76223
|Massman ||25th May 2009 18:42 |
More extreme planned. I could use some of the posts of that thread, though :p
|Massman ||25th May 2009 21:00 |
126 points away from Gold Cup:)
|Massman ||25th May 2009 21:14 |
Biggest problem is the high memory latency
what cooling on the GPU currently?
|Massman ||25th May 2009 21:46 |
Still on air cooling.
I'm trying to reduce the memory latency by reducing the memory divider from the very slow 1066 to 800, but it seems that the increase in HTT frequency (240 -> 325) makes the sideport memory to act up. I have a hypothesis about the problem.
My motherboard is capable of running 533MHz on the sideport memory. Anything higher than 533 (which is the 667 option in the bios) results in an overly artifacted screen, which is a symptom of the memory being overclocked too high. It seems to come down at 667MHz being too much for the sideport memory.
Now, the bios options offered by Asus (533/667/700/...) come across as fixed frequencies. In other words: we think we can set either 533MHz or 667MHz or and so on. Now, I have good reasons to believe that these frequencies are, as everything of the AM2 platform, derived from the HTT frequency, which can also be described as the base frequency. So instead of the three-digit values, we have to see the values as a fraction: 533/200, 667/200 et cetera.
Now, I'm unable to use the following combinations (sideport-htt):
*533/325 => 866MHz real
*533/242 => 645MHz real
*700/200 => 700MHz real
This was part 1 of the puzzle. Part 2 is the actual reason why I'm unable to run 325MHz HTT in combination with (any divider) sideport memory.
Looking at the screenshot I've already posted above, I think you should all be able to guess the reason :)
|Massman ||25th May 2009 21:51 |
|Massman ||26th May 2009 08:42 |
Might be usefull to add this piece of information to this thread. Originally, I found this issue while testing the M3A78-T, which is the same motherboard I'm using in this overclocking journey.
Yesterday, I had a few benchmarks scoring incredibly low for no apparent reason. When I checked the CPU-Z memory details, however, I saw that the memory was clocked at ~480MHz CL5, instead of the 640MHz I set in the bios. Apparently, it was not possible to run with the 1067 divider.
Today, I spent a few hours figuring out what was exactly causing this bizare issue. I went over the different timings, HT Link frequency settings, different combinations and finally ... I figured it out.
To get the 1067 divider working properly at high memory MHz overclocks, enable 2T mode. Even if you're certain the memory could run 1T, it seems to be a technical issue more than a memory bottlenecked issue. If you disable the 2T mode, the bios automaticly resets the memory to the 800MHz divider, even if you've manually put 1067MHz.
By the way, in the proces of figuring out this issue, I also figured out a golden setting for benchmarking .
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