An Overclocking Most Ordinary (2xC2Q)

[kahm]

I found out something rather exciting a couple of weeks ago. As it turns out, both of my Q6600 C2Qs are G0 SLACRs. (Or one was, and I found a second in the course of building my dad's computer. My month old B3 stepping works just fine for him... )

Now, I haven't overclocked since socket A Athlons (the good as gold ~1.8->2.4ghz ones.) The time before that was a pair of Celly 366@550 on a BP6. You get the idea - I'm cheap, lazy, and want guaranteed stability if I'm going to the trouble.

The G0 stepping Q6600s seem ready made for me!

So, without further ado, let's present my victi^M^M^M^M^Mvolunteers:

http://www.flickr.com/photos/silicondependency/2045334728/

Meet Balthasar and Melchior - two of my desktop machines. (Before you ask, yes, there is also a Caspar, but it's hiding in a rackmount and is merely a Socket939 Athlon 4600+. They were named after the Magi computers out of Evangelion.)

Specs:
Balthasar, On the left:
Q6600 G0 Intel Core 2 Quad
Gigabyte P35-DS3R
4gb Rendition (cheap) DDR2-800
EVGA 7800GT CO 256mb
5xMaxtor 500gb SATA2
Antec Truepower 550watt
Lian Li PC-70 mkII
Kubuntu 7.10 64-bit

Melchior, On the right
Q6600 G0 Intel Core 2 Quad
Asus P5K
2gb OCZ Platinum DDR2-800
EVGA 8800GTS 640MB Superclocked
1xMaxtor 500gb SATA2
Antec Truepower 550watt
Lian Li PC-70 mkI
WinXP/WinXP-JP dual boot

Balthasar, with it's 4gb of ram and mere 7800GT runs 64-bit Linux as my desktop solution. I'm hoping to wring a few extra mhz out of it, but it isn't that crucial. Melchoir, on the other hand, is my "Wintendo" for playing my video games and I'm planning on wringing it till it cries

As long as I don't have to do too much work in the process.

Now, the tools of the trade:

http://www.flickr.com/photos/silicondependency/2045334738/

A pair of Thermalright Ultra 120 Extremes, with Scythe S-Flex SFF21F 120mm fans and Arctic Silver 5.

I've never used Arctic Silver before, but I figured I might as well *try* and do it right this time...

The fans were a random pick off the shelf but, in hindsight, they seem to be well regarded. 1600RPM, 63.7CFM, 28dBA, 0.2amp.

The heatsinks themselves need no introduction. However, in a fit of laziness/fear of voiding warranties/destroying $800 of equipment, I'm not going to lap anything. So there.

The first problem to overcome is the cases. The Lian Li PC-70 is an outstanding case - massive, easy to work on, and with a beautiful fit and finish. I love them. However, they're a bit of an older design, and are limited to pairs of 80mm fans for cooling - 6 in total. (2 at the front in front of the HD cage, two behind the CPU socket, two above the power supply.)

Now, I've never done much with the stock loadout of 4 - I even think one of the fans in Melchior is half dead, ATM. So, I decide a cooling refresh is required and back to the store I go.

While I was at the store, a nosy clerk decided to see if he could offer any advice. I told him which cases I was trying to cool and he told me that they were kind of old, and maybe I should replace them.



Now, they *are* older cases, but I'm not about to replace $600 worth of near-mint Lian-Li Full Tower cases for the privilege of using 1 120mm fan instead of 2 80s! I wasn't sure if I should laugh in his face or just start to cry...

http://www.flickr.com/photos/silicondependency/2045334744/

I ended up with a pair of silver 4-channel fan speed controllers good for 18 watts/channel, and 8 shiny new high flow 80mm fans. They're just cheap ones, though - I was going to buy Panaflos until I saw the price the store had on them - a tear inducing $14.95/ea. What I ended up with are rated at 0.28A and have good airflow at 12v and are quiet at 7v. I'll be using the fan controllers to crank up the cooling when I'm playing games.

Six of the new fans are destined for Melchior. The leftover pair will probably end up in Balthasar along with the best fans out of my older stockpile of junk. (Including a pair of Nidec Beta SL 80mm)

I'm going to start off with Melchior for now, and see how well it works out before I break down my main desktop. Well, that and I have a couple weeks vacation time off work and I want to get some PC-gaming action going on.

I'm downloading some benching software right now, and I'll be back with the stock/Intel HSF numbers in a bit.

 

[kahm]

Well, I've got most of the numbers in.

Stock HSF/Stock Speeds
Core temps (Idle): 45 44 43 43
Core temps (load): 68 68 65 65

Thermalright HSF/Stock Speeds
Core temps (idle): 30 30 28 27
Core temps (load): 47 47 43 43

Thermalright HSF/3420mhz
Core temps (idle): 48 48 45 44
Core temps (load): 68 68 61 61

My least insane settings netted me a 3420mhz clock.

Problem is, my cpu seems like a voltage hog. I can get it stable at 3.55ghz, but only by setting the bios to 1.6v, which shows in CPU-Z as 1.50 and a bit volts, sagging to 1.38 under load. Temps maxed at around 72 degrees.

I seems to be stable at the 3420mhz speed, but my voltage has to be set to 1.55v in the bios, which is 1.48v idle and 1.352 loaded. Temps are ~68 degrees under load, which is fine.

3Dmark06

Stock/Stock: 11042 (CPU score of 3843)

Thermalright/3420mhz: 11924 (CPU score of 5333)

 

[equalme]

Well, I've got most of the numbers in.

Stock HSF/Stock Speeds
Core temps (Idle): 45 44 43 43
Core temps (load): 68 68 65 65

Thermalright HSF/Stock Speeds
Core temps (idle): 30 30 28 27
Core temps (load): 47 47 43 43

Thermalright HSF/3420mhz
Core temps (idle): 48 48 45 44
Core temps (load): 68 68 61 61

My least insane settings netted me a 3420mhz clock.

Problem is, my cpu seems like a voltage hog. I can get it stable at 3.55ghz, but only by setting the bios to 1.6v, which shows in CPU-Z as 1.50 and a bit volts, sagging to 1.38 under load. Temps maxed at around 72 degrees.

I seems to be stable at the 3420mhz speed, but my voltage has to be set to 1.55v in the bios, which is 1.48v idle and 1.352 loaded. Temps are ~68 degrees under load, which is fine.

3Dmark06

Stock/Stock: 11042 (CPU score of 3843)

Thermalright/3420mhz: 11924 (CPU score of 5333)

Wow. What did you set your FSB/multiplier at?

With my Q6600 running at 400x8 @ 3.2ghz, and my 8800GTS at 620/1750, I am only netting around 11244 in 3DMark06 w/ a CPU score of 4399 . I really doubt 220mhz would make that big of a difference....

 

[kahm]

I was using 9x380. for 3420. Turns out that was only held up under prime95 for a couple of hours, though. I'm now under 9x375 for more than 13 hours, so that's probably where I'll leave it.

I am kind of glad I'm not the only one who can't hold 3600mhz under air for these things, though

Oddly enough, my second computer using a different motherboard, but basically identical case and cooling, looks like it's going to hit the *exact* same speed stable. (Slightly less voltage - the second chip seem much happier at 9x400=3600 than the first, but I'm not going to push it as hard...)

 

[kahm]

Here are the full sets of numbers I managed.

CPU (Q6600)
Stock: 2400 @ 9x266
OC: 3375 @ 9x375

Video card (EVGA 8800GTS 640MB)
Stock: 575 / 850
OC: 620 / 1035

PCMark 05
Stock: 7777
OC CPU: 9865

3dMark 05
Stock: 14758 (CPU - 10069)
OC CPU/VID: 19358 (CPU - 14161)

3dMark 06
Stock: 11043 (CPU - 3843)
OC CPU: 11869 (CPU - 5291)
OC CPU/VID: 12918 (CPU - 5274)

I'm not 100% sure on the video card yet, but it's very close to stable at those numbers.

I'm still working on the 2nd computer. I think it's going to be the same as the first for the CPU - 9x375, but it also seems to require slightly less voltage. I won't be OCing the 7800gt in it either...