Overclocking Mac Pro 5,1 8Core xeon

With a proper liquid cooling system, Xeon & i7 can gain up to 45% clock speed. For example, hexacore Xeon W3680 is rated 3.33 GHz. I've been running it at 4.7 GHz on a PC for over a year now without problems, it's cool by a large radiator with four 120 mm 2000 RPM PWM fans. So it is definitely loud when running it at full load, but it has saved a tone of times as I do a lot of renderings.

Overclocking Mac Pro is not recommended, because it is engineered for to be a quiet workstation. That's an important feature in a office environment. The downside is its air cooling system can't handle anything beyond the minimum clock speed. So if one would overclock a Mac Pro without changing to a better cooling system, it would overheat and lockup, potentially damaging the hardware permanently.

BTW, more RAMs would launch applications and load files faster. But they would not add any advantage to CPU process tasks such as rendering images and videos.

Overclocking is an amusing hobby. But it yields very little additional useable compute power at tremendous risk to your expensive Hardware.

Most Mac Pros are not compute-bound. They are very, very often I/O bound due to inadequate numbers of drives or too much competition for a single drive.

If Activity Monitor shows you are, in fact, compute bound, you could upgrade a 5,1 to fast dual hexacore processors.

Here is a single hex-core 5.1 running two instances of handbrake

samm1551995 wrote:

Hey guys,

Is it possible to Overclock my dual quad core xeons in my Mac Pro 5,1? and what is the highest stable clockspeed?
also at this higher speed, can i still install a GTX680 or the upcomming GTX7xx equivalent?...

Do you think that perhaps you'd get a simpler and less dangerous performance boost by increasing your RAM beyond 8GB, thus keeping your HD's speed more out of the performance equation?

24GB memory (as 3* 8GB ECC DIMMs) for that Mac Pro tower, from several reputable, Mac-centric vendors can be had for under US$250.

"It works in your MAC,

or your Money BACK."

http://www.datamemorysystems.com/apple-mac-pro-8-core-2-x-quad-core-intel-xeon-w estmere-2-4ghz-mc561ll/a-mid-2010-memory-upgrades/

http://eshop.macsales.com/shop/memory/Mac-Pro-Memory#1333-memory

Mac Pro uses UEFI and you can't go in.

A dual Xeon is harder, though as the eVGA SR-X and SR-2 showed it is possible. Though there most go for buying cheaper processors and then OC - rather than start with a pair of X5680s @ $1600 each!!

Games love high clocks and don't need 8 or 12 cores.

You can build a nice PC for the cost of one 5680, GPUs extra for sake of it as you can spend $250 to $1200 on 2-3 nVidia GTX 680s.

You cannot easily put 2-3 GTX 680s in Mac Pro and no support for SLI. And there are advantages to some pro apps havng a GPGPU one that requires some 8-pin cables.

The G5 LCS was a mitigated disaster for about 50% of the units - the Quad G5, the 2,7DP. Noise? I could not hear myself think with those G4 MDD 1.25DPs.

My Mac Pro is my space heater.

Short form: Dunno.

Long form: Maybe. I do recall some Russian forum that showed how to overclock a Nehalem by (boy, I really hope I remember this right) cutting or shorting some of the PLL (?) leads going to the processor. It's the only hardware or "pin mod" I've ever seen for a Nehalem.

If its something you want to try, download the processor data sheet & try to figure it out. The downside is that unless you are really good at reflowing circuit boards things get kinda permanent.

Personally, I've always been big on voiding my warranties early. Up to you tho'.

R

Found something. Guess the ol' brain has a few years left!

http://hwbot.org/article/newsflash/832_pinmod_for_core_i3i5i7_by_pain_666

There WAS a software overclocking tool for Mac Pros (ZDNet Clock) that I played around with before, but it seems to be broken in Mountain Lion and will probably not be updated. I think it would still work if I could get past the message saying that "you need a Mac Pro to use this tool". Sad because I wanted to try a real speed test with it just once.

But I do not consider overclocking a Mac permanently a good idea. Lots of fuss and lots of risk with very little benefit. More RAM is a cheap speedup for your Mac, unlike mine. Curse you, super-expensive 2008 Mac Pro DDR2 FBDIMMs!

You can overclock the Mac Pro, just not as much (wow, 45% is impressive!). It has an air cooling system, but it seems to be quite a good air cooling system with nice heatsinks. I've put it up to 3.1GHz from 2.8GHz before without problems, though the limiting factor in my case was the overclocking tool that was kind of a hackjob and would cause a kernel panic at higher clock speeds not due to heat problems.