[QUOTE=stars10250;149439][URL="http://www.mersenneforum.org/member.php?u=322"]db597[/URL], I'm reluctant to oc because I've never done it and generally one needs a more expensive motherboard to do so. With the more expensive motherboards, they tend to use better ram (I was considering cheap DDR2 PC6400), and then often a video card. I suppose there are tons of instructions for the oc'd q6600 by now, so I guess I should try it. In my price estimate, I was considering an intel motherboard that costs around $85 which people have said doesn't oc. If you know an inexpensive one to use instead, let me know. I'll start researching this, as I've also heard good things about its oc ability.[/QUOTE]

Overclocking these days is pretty simple - the options are all in the BIOS. Also, the P45 motherboards are all rated for 1333MHz FSB, so with the 1066MHz FSB Q6600 you're not even overclocking the motherboard at all (only the CPU).

The Penryns and the Q6600 are both going to be similarly bottlenecked by the RAM (both don't have low latency integrated memory controllers) - so if you're going the cheap DDR2 route, I'd still advise going for DDR1066. The price difference isn't huge these days, and it makes a significant impact on performance. Either way, they're still a lot cheaper than DDR3.

In terms of motherboards, I've been very happy with the Gigabyte EP45 series. You might want to have a look.

I ordered the EP45 last night with a Q6600, DDR21066, good heat sink, cheap video, etc. The build price (after a ton of rebates from newegg and w/o case) is around $360. I've also spent the time reading up on overclocking, but I'm still a bit nervous. I guess worse-case I'll just run it stock if I can't figure out oc. If things work out well I'll by a second one, as my goal is to best the i7's performance for less $ (including a margin for the added electrical costs). I'll post detailed specs when my experiment is complete.

[QUOTE=stars10250;150079]I ordered the EP45 last night with a Q6600, DDR21066, good heat sink, cheap video, etc. The build price (after a ton of rebates from newegg and w/o case) is around $360. I've also spent the time reading up on overclocking, but I'm still a bit nervous. I guess worse-case I'll just run it stock if I can't figure out oc. If things work out well I'll by a second one, as my goal is to best the i7's performance for less $ (including a margin for the added electrical costs). I'll post detailed specs when my experiment is complete.[/QUOTE] Overclocking is very simple, at least on my EP45-DS4 motherboard - just set FSB to 400MHz and CPU multiplier to 8 and you'll have a 3.2GHz machine.

Whooo Hooo!!! My first benchmark on my Quad
 

Q9550 2.83 (NOT OC'd)
4GB Ram DDR2-1066
Vista-64
L1 Cache 32KB
L2 Cache 6 MB
[CODE]Compare your results to other computers at http://www.mersenne.org/bench.htm
Intel Pentium III Xeon processor
CPU speed: 2833.01 MHz, 4 cores
CPU features: RDTSC, CMOV, Prefetch, MMX, SSE, SSE2, SSE4
L1 cache size: 32 KB
L2 cache size: 6 MB
L1 cache line size: 64 bytes
L2 cache line size: 64 bytes
TLBS: 256
Prime95 64-bit version 25.7, RdtscTiming=1
Best time for 768K FFT length: 14.315 ms.
Best time for 896K FFT length: 17.312 ms.
Best time for 1024K FFT length: 19.695 ms.
Best time for 1280K FFT length: 24.660 ms.
Best time for 1536K FFT length: 30.352 ms.
Best time for 1792K FFT length: 36.097 ms.
Best time for 2048K FFT length: 40.171 ms.
Best time for 2560K FFT length: 52.687 ms.
Best time for 3072K FFT length: 64.813 ms.
Best time for 3584K FFT length: 77.192 ms.
Best time for 4096K FFT length: 86.378 ms.
Best time for 5120K FFT length: 110.774 ms.
Best time for 6144K FFT length: 134.046 ms.
Best time for 7168K FFT length: 162.474 ms.
Best time for 8192K FFT length: 177.730 ms.
Timing FFTs using 2 threads.
Best time for 768K FFT length: 7.583 ms.
Best time for 896K FFT length: 9.068 ms.
Best time for 1024K FFT length: 10.481 ms.
Best time for 1280K FFT length: 12.761 ms.
Best time for 1536K FFT length: 15.739 ms.
Best time for 1792K FFT length: 18.723 ms.
Best time for 2048K FFT length: 21.028 ms.
Best time for 2560K FFT length: 27.472 ms.
Best time for 3072K FFT length: 33.636 ms.
Best time for 3584K FFT length: 39.994 ms.
Best time for 4096K FFT length: 45.127 ms.
Best time for 5120K FFT length: 57.362 ms.
Best time for 6144K FFT length: 69.912 ms.
Best time for 7168K FFT length: 84.464 ms.
Best time for 8192K FFT length: 93.099 ms.
Timing FFTs using 3 threads.
Best time for 768K FFT length: 10.788 ms.
Best time for 896K FFT length: 11.471 ms.
Best time for 1024K FFT length: 21.142 ms.
Best time for 1280K FFT length: 11.142 ms.
Best time for 1536K FFT length: 13.561 ms.
Best time for 1792K FFT length: 16.093 ms.
Best time for 2048K FFT length: 18.102 ms.
Best time for 2560K FFT length: 23.742 ms.
Best time for 3072K FFT length: 28.923 ms.
Best time for 3584K FFT length: 33.718 ms.
Best time for 4096K FFT length: 37.996 ms.
Best time for 5120K FFT length: 46.522 ms.
Best time for 6144K FFT length: 56.103 ms.
Best time for 7168K FFT length: 67.684 ms.
Best time for 8192K FFT length: 74.683 ms.
Timing FFTs using 4 threads.
Best time for 768K FFT length: 10.147 ms.
Best time for 896K FFT length: 11.036 ms.
Best time for 1024K FFT length: 17.728 ms.
Best time for 1280K FFT length: 10.069 ms.
Best time for 1536K FFT length: 10.855 ms.
Best time for 1792K FFT length: 12.564 ms.
Best time for 2048K FFT length: 14.444 ms.
Best time for 2560K FFT length: 18.652 ms.
Best time for 3072K FFT length: 22.751 ms.
Best time for 3584K FFT length: 26.769 ms.
Best time for 4096K FFT length: 30.662 ms.
Best time for 5120K FFT length: 37.507 ms.
Best time for 6144K FFT length: 45.039 ms.
Best time for 7168K FFT length: 53.756 ms.
Best time for 8192K FFT length: 60.621 ms.
Best time for 58 bit trial factors: 2.995 ms.
Best time for 59 bit trial factors: 3.010 ms.
Best time for 60 bit trial factors: 3.414 ms.
Best time for 61 bit trial factors: 3.634 ms.
Best time for 62 bit trial factors: 4.097 ms.
Best time for 63 bit trial factors: 5.227 ms.
Best time for 64 bit trial factors: 5.676 ms.
Best time for 65 bit trial factors: 6.295 ms.
Best time for 66 bit trial factors: 6.244 ms.
Best time for 67 bit trial factors: 6.207 ms.[/CODE]

Can someone tell me why it thinks I have a PIII Xeon?

And why it thinks I only have 6MB L2 Cache? Jeff #371 also shows 6Mb. My vendor tells me I have 12 MB.

[QUOTE=petrw1;150454]Q9550 2.83 (NOT OC'd)
4GB Ram DDR2-1066
Vista-64
L1 Cache 32KB
L2 Cache 6 MB

Can someone tell me why it thinks I have a PIII Xeon?

And why it thinks I only have 6MB L2 Cache? Jeff #371 also shows 6Mb. My vendor tells me I have 12 MB.[/QUOTE]

Ok...so now I did a Manual Communication and I NOW have a second computer line added (for the same computer ... same name) but the second one shows as a Q9550. However, the first entry still has shows the assignments, progress and a Green T. The new entry has a Yellow U.

OOPS....another Man. Comm and the Yellow U changed to a Green T.

So taking a chance I dropped the first Xeon entry ... but that also dropped all my Assignments even though they are still active.
Doing another Man. Comm did NOT get the Assignments showing again.

Exponent Status shows it assigned to ANONYMOUS.

Not wanting to risk losing the credits I am going to now try dropping the assignments locally.

And it gave me back the same exponents.

Anyone know why Prime95 thinks I have 6 Mb L2 Cache instead of the 12 Mb the computer comes with (or was supposed to)?

[QUOTE=petrw1;150653]Anyone know why Prime95 thinks I have 6 Mb L2 Cache instead of the 12 Mb the computer comes with (or was supposed to)?[/QUOTE]Because no core has access to more than 6 MB (MBytes not Mb Mbits) L2 cache. Anyway George explained on the forum that the program has no special coding for caches above 1 MB.

Jacob

[QUOTE=petrw1;150653]Anyone know why Prime95 thinks I have 6 Mb L2 Cache instead of the 12 Mb the computer comes with (or was supposed to)?[/QUOTE]

The Q9550 is really two separate dual-cores sandwiched together. So 2 cores share 6MB of L2 cache and the other 2 cores share 6MB of L2 cache. The 12MB of L2 cache is a little misleading although not incorrect.

Jeff.

I just got my $360, Q6600 rig up and running at 3.2 Ghz OC, 1600 MHz rated FSB. I have to say, for having never done this before it really wasn't all that bad. It took me about 5 hours and 30 or so reboots, but I think I have it running stable now. I'm now in the process of finding out how low I can go with all the voltages and keep it stable. I ran a benchmark on it and got 47 ms for a 2560K FFT, which seems great to me. I'll try to report back on quad performance when it gets past the initial stages of the calculation.

I know this sounds crazy, but I'm starting to think I can beat a stock 920 i7 (2.66GHz) with this thing. This just seems too good to be true. My goal was to maximize performance/cost, and I think this has to be it.

[QUOTE=stars10250;150736]I just got my $360, Q6600 rig up and running at 3.2 Ghz OC, 1600 MHz rated FSB. I have to say, for having never done this before it really wasn't all that bad. It took me about 5 hours and 30 or so reboots, but I think I have it running stable now. I'm now in the process of finding out how low I can go with all the voltages and keep it stable. I ran a benchmark on it and got 47 ms for a 2560K FFT, which seems great to me. I'll try to report back on quad performance when it gets past the initial stages of the calculation.

I know this sounds crazy, but I'm starting to think I can beat a stock 920 i7 (2.66GHz) with this thing. This just seems too good to be true. My goal was to maximize performance/cost, and I think this has to be it.[/QUOTE]

I once had a stress test fail at 141 hours! When you are overclocking, I highly recommend you don't stop the stress testing for a couple days at least!

[URL="http://tinyurl.com/685awu"]http://tinyurl.com/685awu[/URL]

Wow, 141 hours...that's crazy! I thought 24 hrs was a good enough indicator of stability. Mine is still chugging along at 3.2 GHz for about 20 hours now, 43 degrees Celsius across all 4 cores. When this board (Gigabyte GA-EP45) goes unstable, or unstable to me anyway, all it does is slow down to its default speed of 2.4 GHz. Maybe it has some sort of throttle set in the bios somewhere. It's funny...the only time it gave me illegal summout errors was when I first booted it with no overclock! My plan was to break it in for a few days at its default speed, and then track the performance gain from OC. But this thing didn't want to do that. Knowing what I know now, I could have just increased the core voltage a bit, and possibly the northbridge voltage to make it stable, but instead I just jumped head first into OC and played with all the settings. I do plan to continue to lower the voltages more, so I can find the stability point, but I note your advice of failure at 141 hours. Maybe it got particularly hot in your room at that time?