HOWTO: Overclock C2D Quads and C2D Duals - A Guide v1.0

Fire488

Limp Gawd
Joined
Sep 14, 2007
Messages
438
Graysky,
I followed your advice on my system overclock and I did all of the tedious tests involved. (it was frustrating at times). I ran a middle of the road overclock on my processor and memory. I added better cooling and kept temperatures as well as ambient room temps regulated. My mobo just recently shorted out for unknown reasons.
I would like to thank you for all of the great information and tremendous amounts of time that you put into this for our benefits.

Thank you!
 

Fire488

Limp Gawd
Joined
Sep 14, 2007
Messages
438
Ya know I just re-read my post and i hope it did not get misconstrued in any way. I truly meant to thank you graysky. I was not blaming you for the mobo failure it was just a failure.
Thanks again.
 

davidm71

[H]ard|Gawd
Joined
Feb 11, 2004
Messages
1,516
Ya know I just re-read my post and i hope it did not get misconstrued in any way. I truly meant to thank you graysky. I was not blaming you for the mobo failure it was just a failure.
Thanks again.
Dude you were riding by the seat of your pants. I'm not surprised I mean I would never take a pencil to my motherboard. I don't have the balls. Not only that 680i, if that was your chipset, has a horrible reputation for overclocking. If it means anything those same parts are probably wicked cheap right now...
 

Fire488

Limp Gawd
Joined
Sep 14, 2007
Messages
438
Asus is going to RMA it so a new one is on the way. It held up flawlessly for one year.
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
@fire - sorry to hear about your board. I didn't misconstrue it. In the first few paragraphs of the guide, I have my disclaimer: "Finally, I take no responsibility for what you do with the information in this guide. Overclock your hardware at your own risk." :)

If you can swap it out, you might wanna get a different chipset. As david said, the 680i isn't the best o/c'er out there.
 

Fire488

Limp Gawd
Joined
Sep 14, 2007
Messages
438
Well, they wont swap it but, I will buy some time with it and get a new board after the holidays. One that supports the i7 and DD3 ram. Thanks again.
 

scoob19

n00b
Joined
Jun 26, 2006
Messages
32
Any idea what the max FSB you should use without attaching a small fan to the NB? I don't have one at the moment, I was probably just going to do a mild 9x333 overclock for my Q6600. Is it dangerous to go higher than that (or is 9x333 dangerous even) without a NB fan like in the article? I haven't overclocked in a while and im sure im just being overly worrisome. Thanks
 

jfcarbel

n00b
Joined
Dec 18, 2008
Messages
2
First off, incredible guide, so detailed, so well written. I never did understand how to calculate DRAM Frequency but your extensive tables and examples helped it finally click - Thanks!

Now on to my question which happens to be about DRAM frequency :)

I overclocked my E6750 to 3.2 by using a 400 FSB. And my BIOS FSB:DRAM Ratio is 5:6
So my DRAM Frequency is 960.

Now my memory is:
Corsair XMS2 CM2X2048-6400C5DHX DDR2-800 (400 MHz)

Now you mentioned in the guide for DRAM Frequency - "don’t exceed the amount for which your specific RAM is rated." From the specs of my RAM, I believe its rated at 800 Mhz for top speed. So if my DRAM frequency is 960, I am then overriding this rating. Correct? How bad is this? Should I use a different ratio, any suggestions?

My machine has been running rock solid and Orthos tests and transcoding of DVDs - all memory instensive work perfect. Never a blue screen.

Is running at 960 not overclocking the memory? I thought you can overclock memory if its a good brand. Is my understanding of overclocking of memory incorrect?
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
Now my memory is:
Corsair XMS2 CM2X2048-6400C5DHX DDR2-800 (400 MHz)

Now you mentioned in the guide for DRAM Frequency - "don’t exceed the amount for which your specific RAM is rated." From the specs of my RAM, I believe its rated at 800 Mhz for top speed. So if my DRAM frequency is 960, I am then overriding this rating. Correct? How bad is this? Should I use a different ratio, any suggestions?

My machine has been running rock solid and Orthos tests and transcoding of DVDs - all memory instensive work perfect. Never a blue screen.

Is running at 960 not overclocking the memory? I thought you can overclock memory if its a good brand. Is my understanding of overclocking of memory incorrect?
That statement I made about not exceeding the specific rating can be taken with a grain of salt. If you're running stable @ 960 MHz, and you don't care if the modules can *potentially* fail sooner as a result, don't worry about it. I wrote the guide that way to help minimize problems for newbies overclocking for the 1st or 2nd time. Once you're comfortable with the system, and want to push harder, I say go for it. Memory prices are so cheap these days that you can replace your DIMMs if you really have to pretty inexpensively. Plus, most good ones carry a lifetime replacement anyway.

To answer your question, yes, 800 @ 960 is overclocking. And yes, if it's quality stuff, you're probably fine doing it.
 

blgdinger

Limp Gawd
Joined
Apr 10, 2005
Messages
202
I have a question about the Rated FSB in CPU-Z.


With stock settings as seen below the Rated FSB is basically 1333 however I OC'd my Q9300 a little to 350 and the Rated FSB went up to 1400. Just exactly what does this mean and don't I want that Rated FSB to not go above 1333? My motherboard is a P5Q-SE Plus which is rated to 1600 so does that mean I'm in the clear?




And does any of this have to do with my memory's FSB? http://newgskill.web-bi.net/bbs/view.php?id=g_ddr2&no=115 is my RAM so does the 533 FSB on it have anything to do with my CPU's FSB? I keep rereading the thread but I'm confused.
 

cyberkost

[H]F Junkie
Joined
Nov 25, 2008
Messages
8,778
graysky -
First, thanks for a great thread!
Second, I see that the last time you edited the OP was on 06-08-2008 -- would you say the recommendation on benchmarking/stressing/monitoring software are still current?
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
@cyberkost - yep. If I had a newer machine (still love my X3360), I'd update the guide with some of the results overclocking whatever I have (probably i7 but I see no need to upgrade util the 32 nm FAB stuff comes out and maybe 6-9 mo. after then). I don't see that the underlying concepts would change though. Maybe I can update the list of available CPUs, but that's about it. Oh, obviously, the version numbers of the software in the guide have probably changes, CPU-Z, coretemp, etc. etc.
 
Last edited:

Impulse

[H]F Junkie
Joined
Apr 5, 2001
Messages
10,232
What would put more stress on the system overall, a 425 MHz FSB x8 (=3.4GHz) running in sync (mem at 850 MHz) or 378 MHz FSB x9 (=3.4GHz) running asynch (mem at 907 MHz with a 5:6 divider), assuming the memory and mobo can both handle either and are stable. Or is it even worth bothering with running a 378 FSB in asynch rather than just running the RAM on a 1:1 divider (756 MHz)?
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
Depends on what "stress" means. To me stress is caused mainly by voltage. You'll have to see what your voltages @ 8x425 and @ 9x378 come out to stable (which is a pretty involved process really) and make the call at that point. Throw the memory divider into the equation too :) I'd take a hunch and say that the lower FSB will require less overall voltage and running the mem 1:1 but you'll have to do the experiments and make the call.
 

Impulse

[H]F Junkie
Joined
Apr 5, 2001
Messages
10,232
Well, I guess by stress I meant which would shorten the rig's lifespan more or, as you said, which would likely require more voltage (I tend to pass my systems down to family members/friends)... One way puts more "stress" on the mobo I guess, while the other taxes the mobo less and the memory more (since it'd run 50MHz higher w/the best available divider), but it's probably gonna take a lot of fiddling to figure out minimum NB voltages (amongst other things) at either FSB and memory divider, heh. I'll let ya know what I end up with.
 

iMpathetic

Weaksauce
Joined
Apr 19, 2009
Messages
68
Quick question (in class and not supposed to be doing this) --

I have a Q6600 G0 running under a Thermaltake Big Typhoon. Settings are 1.38V, 9x400. Idles are in the mid 30s and loads are in the mid 60s. Do you guys think I have any potential of reaching 3.8 or even 4GHz semi-stably? (Not 100% load all the time, maybe 100% for a minute, like stress test, etc. I overclock for fun, I don't need the speed at all. I could honestly be using a netboox and not feel a difference. I don't stress it in the slightest.)

Thanks for your help!
 

Impulse

[H]F Junkie
Joined
Apr 5, 2001
Messages
10,232
Only way to know is to test it, but if it requires any more voltage (and thus heat) it's probably not worth it at all (for a 5-10% boost, if that)... Then again it depends on what you mean by 'semi stable', for me there's no such thing. :p If you just wanna boot into Windows to see it running at 4GHz on CPU-Z then go for it, heh.
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
+1 for what impulse said. If you're not using the box for anything critical (processing photography/artwork, video editing, etc.) I guess you can run an 'unstable' overclock since any data you lose you don't really care about. That said, I don't understand why you would want to but hey, it's your hardware.
 

blgdinger

Limp Gawd
Joined
Apr 10, 2005
Messages
202
Most good boards will offer several fsb:dram dividers. Some common ones are listed below. Assuming that you’re using a 333 MHz FSB the ratios are:
Code:
FSB : DRAM
1:1 = 333 MHz : 667 MHz
4:5 = 333 MHz : 833 MHz 
2:3 = 333 MHz : 1,000 MHz
5:8 = 333 MHz : 1,066 MHz
3:5 = 333 MHz : 1,111 MHz
1:2 = 333 MHz : 1,333 MHz
Now, if you’re running @ a 400 MHz FSB, the ratios become:
Code:
 FSB : DRAM
1:1 = 400 MHz : 800 MHz
4:5 = 400 MHz : 1,000 MHz 
2:3 = 400 MHz : 1,200 MHz
5:8 = 400 MHz : 1,280 MHz
3:5 = 400 MHz : 1,333 MHz
1:2 = 400 MHz : 1,600 MHz
You can calculate these yourself with this formula:
Code:
DRAM Final Clockrate = (2 x FSB)/Divider
Example, 2/3 divider @ 400 MHz FSB: (2 x 400 MHz)/(2/3) = 1,200 MHz
If my ram is rated at 1066 @ 333mhz FSB and it goes up to 1280 @ 400mhz FSB then all that does is tell me I havea 5:8 ratio correct? How does this correlate to the whole OC process? Also should I just leave the memory at 1280 or put it back down to 1066?
 

cyberkost

[H]F Junkie
Joined
Nov 25, 2008
Messages
8,778
1. Potentially your BIOS has an option to change the ratio. There's a case for simple ratios (1:1, 1:2) being "better" (faster, all other things equal) than the complex ones (2:3, 5:8, etc). If your mobo supports 500MHz FSB (most don't), then you're better off running 1:1 (and mem @ 1000MHz), than 1066MHz at 5:8
2. Another thing is timings ... those 4-4-4-12 numbers ... I'm going to make a somewhat controversial statement, but it'll give you the idea: "1000MHz @ 5-5-5-15 is potentially faster than 800MHz @ 4-4-4-12, but by no means the delta is 25% as the MHz number might imply"
 
Last edited:

Aznboy1993

2[H]4U
Joined
Nov 9, 2009
Messages
2,080
Thanks! Very good and informative guide sir!

I have my C2D E8400 C0 at 4.2GHz with 1.38v coupled with my Asus Rampage Formula. Is that good?
 

graysky

Gawd
Joined
May 6, 2007
Messages
620
...if someone wants to donate the hardware, I'd be glad to update the guide on the i7 series :p
 

ballistic

Gawd
Joined
Feb 8, 2002
Messages
740
Any idea what the max FSB you should use without attaching a small fan to the NB? I don't have one at the moment, I was probably just going to do a mild 9x333 overclock for my Q6600. Is it dangerous to go higher than that (or is 9x333 dangerous even) without a NB fan like in the article? I haven't overclocked in a while and im sure im just being overly worrisome. Thanks
What board are you on? You should be fine as I don't even need to touch any voltages to do 9x333 on my Q6600, on a Gigabyte P35-DS3L, Abit IP35 Pro and Gigabyte EP-45 UD3R
 
Last edited:

014

Limp Gawd
Joined
Nov 6, 2010
Messages
193
It's 4 years later, and I'm replying to say thanks. I finally understand a bit more how the elements are related when your goal is to achieve an overclock. I need to torture my CPU for a day, but I have finally gotten my system to at least boot and run Prime95 for 30 minutes with a Q6600 clocked at 3.4GHz, cooled by a Corsair A50. Max temp reached under Prime95 so far was 61C. Thanks!
P.S. I am just letting the system choose the vcore voltage automatically since I'm just getting it started. I'm happy enough at this point that I can use the computer. :p
 

RockoW

Limp Gawd
Joined
Feb 25, 2007
Messages
136
I guess this question goes in here. I've been reading and learning about how to OC a Q9550 (on air) with my Asus P35, and I've setup the starting points in my BIOS.
Just wondering if there is anything that looks terribly wrong and that needs to be changed?
I only have a mild overclock in mind, I have no intentions on trying to get to 4GHz. I don't even think my mobo can do that.
I have 1066MHz memory. Is there a point in setting them to 800MHz in BIOS and let the mem follow the FSB up?

Thanks in advance. :)



 

aphasia

[H]ard|Gawd
Joined
Jan 15, 2011
Messages
1,137
wow thread necro.

i'ved linked to this thread a few times b/c the op's info is fantastic.
on another side not, can't wait till UEFI becomes more mainstream as seeing large blurry pics of BIOS screens will become a thing of the past (in build screen capture).

back on topic...
regarding RockoW post, suggest you go to first page and do your OC in the methodical way the op suggests. it'll be more time consuming but your results will be better.

just on what you posted, the voltages look fine accept maybe the CPU PLL. can't remember if 1.50v is on the high side or not. unless someone else jumps in, perhaps set it to 'auto' save and reboot and reload bios to check the default.

'Load Line Calibration' when enabled (it's disabled on your pic) can help stability during load especially with higher clocks. you'll need to look at NB volts as well as your FSB gets higher (350+).

regarding RAM frequency, just change it to manual and change your FSB to desired value then go back to RAM freq and change it to 1066 or below.
also changing the 'FSB strap to Northbridge' will give you a greater variety of 'RAM freqs' values to play with.
 
Last edited:

RockoW

Limp Gawd
Joined
Feb 25, 2007
Messages
136
Thanks for the reply. :)

The CPU PLL is set at it's lowest there. I read that you dont wanna go over 1.55V on the Q9550. I think the next increment is 1.6V so I can't really touch it. :(

My BIOS doesn't seem to be the most overclock friendly. I dont think I can set the frequency of the RAM manually. I can however select from the standardized values. 800MHz, 1066 MHz and lower.

I read somewhere that LLC could be harmful to 45nm CPUs. And that if you weren't gonna go for 4GHz+ OC you could leave it to off.
 
Top