I was looking through some of the top computers and was amazed when I saw this result by a 4.8 Ghz Pentium D:

http://setiathome.berkeley.edu/result.php?resultid=402064927

I didn't even know you could overclock a system so high. Makes me wonder what kind of rig this guy is running.

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I'll wager a phase change cooled Rev C1 or D0 D945, 960 or an Extreme D965.
Could reach this on a Asus P5W-DH.

What makes this especially impressive is that the OC runs stable enough to validate at this speed.

Since we're guessing, any other ideas?

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Question though, is it actually that much faster than other computers with same, or similar cpu's. It is still taking twice as long as my normally clocked core 2 duo per similar AR units.

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It's actually an EE - when you go to the computer details, you see the default clock it runs as and how many CPUs it has.

"GenuineIntel Intel(R) Pentium(R) D CPU 3.46GHz" and 4 CPUs - bound to be an EE 955.

HTH,
Simon.

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I didn't even know you could overclock a system so high.

P4 3.8GHz OCed to 6.0GHz


Pentium D 830 @5.4GHz

Opteron 146 @ 3.5GHz

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Well, my measly 50% overclock (P-D 805, air-cooled) from 2.66 to ~4 GHz sure pales in comparison ;o)

Seriously though, using phase-change cooling you can do amazing things clockspeed-wise. For a sky-high overclock like the ones you posted to run stably, water probably isn't enough.

An Asetek Vapochill or a Chip-Con Prometeia or similar compressor/phase change setup costs a pretty penny, but you can usually hold off on upgrades for a while ;o)

Regards,
Simon.

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Found on Ocforums.com

If anyone is interested its a pentium D 955ee @1.4volts under a modded machII motherboaerd is an asus p5wd2 premium with vdroop mod extra cooling on northbridge and mossfetts 1gig of ocz pc6400 platinum el, a 74 gig raptor and a radeon x800 xl i have had it up to 5ghz but i wanted stability, sofar rig has been running 24/7 for one month without any shutdowns

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Overclock with the MSI G31M3-L and Intel E8600 3.33Ghz
Intel D865GLC Socket 478 Motherboard
~How To Overclock The Eee ASUS 1005HA Netbook To 1.9Ghz~

Here's an article I found on installing a Vapochill LightSpeed. It also explains Vapor Phase Change Cooling more in depth.

http://www.systemcooling.com/vapochill_ls-01.html

Honestly, it seems like a lot of work to set this up. The money may be better put to use by buying better processors, etc.

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I was looking through some of the top computers and was amazed when I saw this result by a 4.8 Ghz Pentium D:

http://setiathome.berkeley.edu/result.php?resultid=402064927

I didn't even know you could overclock a system so high. Makes me wonder what kind of rig this guy is running.

That link appears to have expired. Here is a link directly to that computer:

http://setiathome.berkeley.edu/show_host_detail.php?hostid=2402415

Click on one of his completed result id's to see his cpu speed. Right now this computer is listed as the Top 94 computer. It is also getting better RAC than my 2.66Ghz Core 2 Duo (not overclocked).

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The reported CPU clockrate is fallible.
My Core 2 is shown running at 3643MHz when in fact it is actually running at 3238MHz.

The multiplier is actually 8x in my case, but the code assumes the multiplier is 9x!

Andy is somewhat correct,

"The reported CPU clockrate is fallible."

The value shown in result <stderr> area of results from Simon's Team optimized cruncher varies a bit, has a hickup now and then (wildly wrong), but is normally fairly accurate.

(Andy - Please see what CPU-Z says about your CPU MHz speed-that is the most accurate report I know of)

It is the output of calling an Intel Library function "What is this CPU's MHz speed". The reason it is variable is the Intel programmer didn't carefully make sure that the code kept using the same CPU/core/thread throughout the calculate MHz function.

If you look at many result files, however, and you find a specific number being repeated, then that is the MHz speed. (CPU real speed: 4837 MHz)

How is it computed. I do not believe it looks at Multiplier or FSB speed information, as there are SOO many different CPUs/chipsets which all report this information differently. Each would require their own set of source code to reaad. Instead it does what most MHz calculators do:
1. find a hardware clock in software
2. note a starting time (after the clock tick changes)
3. note the CPU's internal cycle counter value
4. wait a specified period of time
5. wait til the hardware clock tick changes (trailing edge)
6. note the CPU's cycle counter at end time.
7. MHz speed = (cycle_end-cycle_start) / (end_timer-begin_timer)

Agreed! CPU-Z will give you Actual Info on your System!

I have one of My Work Unit Result's HERE: that states My CPU Speed @ 3051MHz

But My Actual CPU Speed is 2648.5MHz

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Right Jw,

But although you did find that odd one...I checked 4 random results of yours...and the MHz speeds listed were 2648 +/- 4.

That machine seems to be throwing a fair number of "Compute error" type failures. It may be fast, but if 30%, (guesstimate based on the results pages I looked at now), of it's work is trashed, then what is the point?

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Wave upon wave of demented avengers march cheerfully out of obscurity into the dream.

When i overclock my systems the most important thing is stability and not getting client errors. i have had 4 client errors recently one of these 6 other people who had this wu also had client error the other three were my fault as i pushed a little too far so i have backed it down a little to get things stable.

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It's also important to watch power consumption when overclocking, at least if you are running multiple hosts :o)

If you push things too far, the power consumption of your CPU rises exponentially for a negligible increase in processing speed.

I'm actually undervolting my P4's to get the best bang for the buck...

Regards Hans

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Andy is somewhat correct,

"The reported CPU clockrate is fallible."

The value shown in result <stderr> area of results from Simon's Team optimized cruncher varies a bit, has a hickup now and then (wildly wrong), but is normally fairly accurate.

It's completely accurate for my overclocked Celeron.

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That machine seems to be throwing a fair number of "Compute error" type failures. It may be fast, but if 30%, (guesstimate based on the results pages I looked at now), of it's work is trashed, then what is the point?

If it is showing a lot of computer errors then that may be a sign this system is crashing a lot. Also, if his getting computer errors that means his is not getting credit for those. Makes me wonder how he is getting so much RAC then.

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I was looking through some of the top computers and was amazed when I saw this result by a 4.8 Ghz Pentium D:

http://setiathome.berkeley.edu/result.php?resultid=402064927

I didn't even know you could overclock a system so high. Makes me wonder what kind of rig this guy is running.

thats nothing i have a pIII overclocked to 50ghz and brings me a beer whenever i run out!!!!

thats nothing i have a pIII overclocked to 50ghz and brings me a beer whenever i run out!!!!

50mhz eh?

Are you sure you don't mean underclocked?

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