Back after a Hiatus

[FloridaBear]

Just built a new core i7 920 PC with an EVGA X58 SLI motherboard and Radion 5770 graphics board (oops, no CUDA--what was I thinking?). I also managed to download and crunch 2 whole SETI WU's, but apparently I restarted crunching at a bad time!

Anyway, I hope to ramp up my RAC in coming days and eventually hit that 1,000,000 mark I fell short of before.

One question that I didn't see an authoritative answer to: would my RAC be better or worse with hyperthreading on? I do see programs like y-cruncher showing modest improvement with HT (whose threads are very similar to each other), so I'd assume SETI throughput may also benefit (slightly). I'd think the benefits for overall RAC might even be better when mixing different project types (I'm crunching WCG too).

Any input would be welcome.

 

[Codeman05]

Welcome back!
Honestly, from everything I've read, HT on seems to have a pretty small impact.
Yes you are crunching 8 WU's at a time vs 4...but your also crunching each WU much slower and in the end it pretty well offsets.
Some guys have had slightly worse performance with HT on, some slightly better.

I don't have any good numbers on this currently, but there has been a few discussions on the Seti forums. I leave HT on, but I set seti to only use 4 cores...that way I'm not really using HT for seti but my system still has the HT cores available to handle other background processes if need be, seems to work rather well.

 

[QuietIce]

back, FloridaBear!

It'll be good to move your name UP in the ranks for a change. You have a few positions to go to get back into the Top 100 with the million mark not too far beyond. Look for your name in the Milestones thread - I'm sure it'll be there either this Sunday or 16 days from now (since I update the milestones every other week). Again, welcome back ...!

 

[Vento1]

back to seti, good to have you back crunching again.

 

[FloridaBear]

I'm currently having some stability issues, and trying to narrow the problem down. As a result, my RAC is going to be well below its potential for awhile. I'm also seriously considering a GTX 260 card (will eBay the 5770) and a RAM upgrade. The OCX 1333 RAM that I have is the primary suspect right now, but I still don't know for sure.

 

[FloridaBear]

UPDATE: I found the culprit. I have one bad stick of RAM, as confirmed by Memtest 86+ (I didn't know that was still around!). So, that stick has been pulled, and I'm now running a mild overclock (3.15 GHz), with memory running 7-7-7-20@1333.

With this setup, y-cruncher 0.4.4 is cranking out 100M digits of pi in about 45-46 seconds.

I had a pretty stable O/C around 3.4 and managed a 41.4 second time. Not too shabby considering my Core2 Duo needed 180 seconds to do the same thing ;-)

 

[FloridaBear]

Well, going on a cruise for a week, which means the Core i7 will be crunching at 3.4 GHz with no interference. Let's see how high I can get my RAC!

 

[QuietIce]

Assuming no interruptions you should at least get over the hump. It takes about two weeks of solid crunching to get the WUs built up in the pending que - after that it's smooth sailing ...!