E6300 -- need advice on overclocking beyond 2.331 Ghz

platbr

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I fininshed my E6300 & Abit AB9 build this weekend and installed XP Pro. Things seem very stable at 333 Mhz FSB (2.331 Ghz core) with the x7 multiplier. My RAM is DDR2-667 Corsair Value Select. I'm currently running stock voltages (vDIMM at 1.8v, vCPU at 1.325v). I can POST beyond 333 Mhz, but Windows won't start. I guess I have a couple questions on voltages, etcs., and what to try next.

1. What voltage for RAM? A post a few down said "pump vDIMM to 2.2v and forget about it." I trust that is the right approach here? Anandtech did a review of this RAM and it looks like they were hitting DDR2-800 at 2.2v (link). So any worries about pumping vDIMM to 2.2v? I'm nervous about voltages, for obvious newbie related reasons. Any concerns overclocking DDR2-667 RAM to DDR2-800?

2. CPU voltage? I get the impression that I don't need to go up much here -- it looks like others are hitting 400+ FSB without any increase over stock 1.325 voltage. Another article hit 370 FSB without much increase (increase to 1.4v -- link). Thoughts here? Is pushing to 1.4v pretty much a no brainer?

3. Other voltages & considerations What else am I missing? Do I need to worry about MCH and ICHIO voltages? I have controls for these -- but do they really matter for modest overclocking?

Thanks in advance...
 

Generals

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when oc'ing, after increasing the cpu voltage, is it a requirement to also increase the RAM voltages? or is it just an option to get more out of the rams?

what is the acceptable or max cpu voltage we can apply that wont affect or shorten che lifespan of the cpu?

i heard that oc'ing shortens cpu lifespan?

thanks
 

kamel5547

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when oc'ing, after increasing the cpu voltage, is it a requirement to also increase the RAM voltages? or is it just an option to get more out of the rams?

what is the acceptable or max cpu voltage we can apply that wont affect or shorten che lifespan of the cpu?

i heard that oc'ing shortens cpu lifespan?

thanks

Yes OCing shortens lifespans.... will u notice probably not. On the other hand the P1's we have in the soil lab would be dead by now if they were oc'd.
 

kwalker

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when oc'ing, after increasing the cpu voltage, is it a requirement to also increase the RAM voltages? or is it just an option to get more out of the rams?

what is the acceptable or max cpu voltage we can apply that wont affect or shorten che lifespan of the cpu?

i heard that oc'ing shortens cpu lifespan?

thanks
The Maximum Vcore for the core2 E6300 is 1.3625
Absolute max 1.55volts
The most important rule in any oc is heat.
Heat will ruin a CPU and not necessarily voltage unless you ignore the guide lines listed.
If your stable and your maximum temps are below 62C you’re not going to have any issues.
Just the same there is always a risk involved.
Good luck
 

platbr

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Well, I think I may have reached my max on this ram, at least. Perhaps the processor, too. I was able to get my ram solid at DDR2-800 (running proc. at stock 266 Mhz) but if I try to run it at DDR2-800 with the proc running at 350 or above, windows won't start. Things seem most stable around 333 Mhz, and changing voltages doesn't seem to make much difference. Even with volts at 1.4v proc and 2.2v memory, things weren't getting better. At 1.4 & 2.2 I was barely able to boot windows in an unstable state.

Suggestions? I'm back at 333 Mhz and 1.325 & 1.8, which seems stable. Temps are 32.0c / 40.0c.
 

kwalker

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try dropping ram to 533 speeds to see if thats holding you back.
ram voltage of 1.95 to start. let bios detect timings (adjust later)
you have room to bump up the ram voltage but thats only to stabilize your oc.
I'm not sure how that Value select will react to voltages of 2.2 volts without heat spreaders.
I've had some Abit mobos that didnt like me so I have been staying with the higher end Asus boards and Loving it.
the mobo might be the hold up .
make sure you have all the latest drivers and Bios.
edited ....I see you have a good psu (thats what these glasses are for) :)
 

illinikevin

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I have a pentium 166 MHz that I oc'd to 215 MHz in 1997 and It's still running. It's in my sisters classroom and her kids use it almost everyday to look at the internet.
 

platbr

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try dropping ram to 533 speeds to see if thats holding you back.
ram voltage of 1.95 to start. let bios detect timings (adjust later)
you have room to bump up the ram voltage but thats only to stabilize your oc.
I'm not sure how that Value select will react to voltages of 2.2 volts without heat spreaders.
I've had some Abit mobos that didnt like me so I have been staying with the higher end Asus boards and Loving it.
the mobo might be the hold up .
make sure you have all the latest drivers and Bios.
edited ....I see you have a good psu (thats what these glasses are for) :)

For ram speed, the mobo only lets you choose 1:1, 4:5, and 2:3 based on 266 Mhz. So I've already got it set at 533 speed (at 333 Mhz this = DDR2-667 at 1:1). It's as slow as it goes. Bios does the timings -- haven't figured out how to change them. They are 3:5:5:15 per cpu-z. Anandtech was running this ram at DDR2-800 at 2.2v in a test (and surprisingly, I got it to work at DDR2-800 with the processor running at 1.86 with 266 FSB).

At 333 Mhz / 2.33 Ghz everything's groovy. At 343 / 2.4, Prime95 starts to have small errors, pretty much regardless of voltages. This might be the mobo. I'm not displeased with these speeds, but the 500+ FSB speeds people are getting with the DS3 made me think I'd get a bit more than 333/2.33. I have the latest bios... hopefully it will get better with time, I guess.
 

kwalker

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I wish you the best.
You do need a good overclocking mobo to have the experience you hunger for.
The best part so far is that you have your core2 and stock is better than most.
Just curious what do you get for superPi 1M ?
 

platbr

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I wish you the best.
You do need a good overclocking mobo to have the experience you hunger for.
The best part so far is that you have your core2 and stock is better than most.
Just curious what do you get for superPi 1M ?

24.265s for 1M. Is that good?
 

platbr

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Just ran SuperPI on my old Dell Dimension XPS P4 2.66 from four years ago. It clocks in around 69.9 seconds for 1M. Definitely nice to see some improvement... you're right about the Core 2 Duo architecture. A nice leap forward. I'm gonna stick with 333 Mhz for now. Seems rock solid stable, which is a plus!
 

Crashman

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First of all, all Corsair documentation I've looked at says their modules are rated to run up to 2.1V or 2.2V, depending on the model.

Second, you can try dropping your RAM speed, some boards change your ratio as you overclock and others do not.

If the board is NOT changing the ratio, setting it to 533 would result it it running at 667, when you overclock the CPU to 333. Knowing whether or not your board automatically changes the CPU ratio to compensate for the overclock is key to reaching the maximum overclock for your CPU.

Your RAM will run 800MHz at 2.1V. Whether it's getting pushed beyond that or not when you overclock is something you'll have to figure out on your own. CPU-Z can tell you.
 

aj6065

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try dropping ram to 533 speeds to see if thats holding you back.
ram voltage of 1.95 to start. let bios detect timings (adjust later)
you have room to bump up the ram voltage but thats only to stabilize your oc.
I'm not sure how that Value select will react to voltages of 2.2 volts without heat spreaders.
I've had some Abit mobos that didnt like me so I have been staying with the higher end Asus boards and Loving it.
the mobo might be the hold up .
make sure you have all the latest drivers and Bios.
edited ....I see you have a good psu (thats what these glasses are for) :)

For ram speed, the mobo only lets you choose 1:1, 4:5, and 2:3 based on 266 Mhz. So I've already got it set at 533 speed (at 333 Mhz this = DDR2-667 at 1:1). It's as slow as it goes. Bios does the timings -- haven't figured out how to change them. They are 3:5:5:15 per cpu-z. Anandtech was running this ram at DDR2-800 at 2.2v in a test (and surprisingly, I got it to work at DDR2-800 with the processor running at 1.86 with 266 FSB).

At 333 Mhz / 2.33 Ghz everything's groovy. At 343 / 2.4, Prime95 starts to have small errors, pretty much regardless of voltages. This might be the mobo. I'm not displeased with these speeds, but the 500+ FSB speeds people are getting with the DS3 made me think I'd get a bit more than 333/2.33. I have the latest bios... hopefully it will get better with time, I guess.

I'm new to overclocking, and all the memory stuff still confuses me. Aren't you using a 4:5 RAM divider now? [5/4=1.25] --> [1.25x266=333mhz (FSB)], like you said. But, if you use a 2:3 RAM divider, can't you get around 400mhz FSB while still keeping your RAM at stock mhz speeds? [3/2=1.5] --> [1.5x266=399mhz (FSB)]? Or you could look at it this way... right now your running a 4:5 divider. [4/5=.8] --> [.8x667=533mhz (RAM)], which is what you said. If you used a 2:3 divider then your RAM would be clocked at only 445mhz. [2/3=.667] --> [.667x667=445mhz (RAM)]. That would give you more overclocking headroom without sacrificing RAM speeds. If I'm wrong or not even making any sense, can you help me clear things up please? Thanks a lot
 

platbr

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Crashman said it right -- the board doesn't change the divider so setting it at DDR2-533 (1:1) results in it running at DDR2-666 when you increase the FSB to 333 Mhz.

This is most clear in the bios because it has a spot that shows what speed you are running your ram at. You know -- what you're really choosing is divider. It says 533, but that really just means 1:1; 666 is just 4:5; and 800 is just 2:3.

Your math didn't quite make sense to me, but we may just be thinking about this differently. DDR2 ram speed is just your FSB multiplied by the divider x 2. So if your FSB is 266, with 1:1 your DDR2 is 533. If your FSB is 266, with 4:5 your DDR2 is 666. If your FSB is 266, with 2:3, your DDR2 is 800. Abit's mobo doesn't let you select divider, though, it has you choose a "speed" based on your CPU's stock FSB (in my case, stock is 266). So if I choose 533, I'm really just choosing 1:1. So if I choose 533 and then upclock my CPU to 333, then I'm really at DDR2-666.
 

aj6065

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I think I get it now. Thanks a lot. But just to get a couple points straight...

If you're going to run at stock 266mhz FSB, and you want to run the divider at 1:1, then the maximum DDR2 speed you can reach is 533mhz?

And if you're going to run at stock 266mhz FSB, then the only way to reach 667 or 800mhz RAM speeds is by using a multiplier?

Thanks again!


Edit: I also figured out what I did wrong in my math. In the first part, I was talking about FSB, when I really meant RAM mhz. And I also forgot to multiply by 2. So when I typed "Aren't you using a 4:5 RAM divider now? [5/4=1.25] --> [1.25x266=333mhz (FSB)]", I really should have typed...[5/4=1.25] --> [1.25x2x266=666mhz (RAM)]
 

platbr

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If you're going to run at stock 266mhz FSB, and you want to run the divider at 1:1, then the maximum DDR2 speed you can reach is 533mhz?

That sounds right to me -- and it isn't so much that the "max" you "can reach" is 533 mhz -- it's just that you've set your ram to run at 533 mhz. You can set it to run at 667 or 800, but that requires a different divider (i.e. 4:5 or 2:3).

Math looks right now, too.
 

Crashman

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Former Staff
I think I get it now. Thanks a lot. But just to get a couple points straight...

If you're going to run at stock 266mhz FSB, and you want to run the divider at 1:1, then the maximum DDR2 speed you can reach is 533mhz?

And if you're going to run at stock 266mhz FSB, then the only way to reach 667 or 800mhz RAM speeds is by using a multiplier?

Thanks again!

Actually that's not quite right. Some boards will adjust the multiplier automatically, but many will not. So choosing 533 for the RAM, then increasing the CPU bus from 266 to 300, will cause the RAM to also go from 533 to 600 on such boards.

This actually insn't the case with most Core2 boards, but its still a possibility.

533 is a 1:1 ratio for the 1066FSB. Both operate at 266MHz. Dual channel mode makes up for the fact that the RAM is Double Data Rate while the CPU is Quad Data Rate.
 

illinikevin

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What is the disadvantage of running say a 333 FSB and having the memory clocked to 400 (or as close to it because of the divider). I'm about to build a new system and was planning on doing this or should I set both FSB and memory to 333?