Help me get a higher overclock!

[matt77]

Hi

Total ocing newbie here who is struggling to work all this out.

I have read up a little and tried to oc and have reached 3.5 ghz on my i7 920 (CO stepping). I did this by simply upping the bclk to 175 with a cpu ration setting of 20, giving me 3.5. CPU voltage is at 1.20000. All other settings are adjusted by bios (I have an asus rampage II extreme btw).

I can't push the bclk or the cpu voltage up any more without blue screening when i run prime 95. I am therefore officially stuck. Is there any way I can try an get passed 3.5 or is that the limit of my chip? Can i change qpi/dram core voltage from 1.2000 to somethihng higher? Will this make a difference to an overclocking sucess? My ram is corsair 6GB XMS3 1600 Mhz CAP9 (DDR3).

Sorry if all this seems ridiulous to you, but I have to start somewhere I suppose!

Thanks for any ideas.

 

[nonxcarbonx]

You have a really good chip to get that high on stock voltages. Just to be safe for now, lower your ram, uncore and qpi multipliers as low as they allow, so ram is probably 6, uncore 12-13(13 is better if your board allows it) and qpi of 18, just so you know those aren't bottlenecking anything. Once you get you maximum cpu freq, raise them as high as you can Don't rely on all of the auto features for dram voltage and qpi/vtt voltage.

I had to raise my voltage after about 3 ghz, so you have a really tough chip. Go ahead and raise it to 1.25-1.35 v because that is almost certainly what is holding you back and try raising your base clock again. If you don't have that high of temps (i would stop at 80-85) keep going and raise voltage/base cloock. Your safe up to 1.375 v vcore, and likely won't have any problems running up to 1.55 v. Maximum recommended vtt/qpi is 1.35 v, but that likely won't need to be raised much because of the lower multipliers. Also, go and disable turbo, speed step and virtualization, as those might get in the way. But you're almost certainly not at you maximum frequency. In fact, I think you can easily surpass 4ghz with the increase in voltage. If your still having trouble, try disabling hyperthreading, as it sucks up some voltage and produces a bit of heat. You can also raise pll voltage up to 1.88 v, but I don't know much about that because my crappy foxconn motherboard's bios doesn't let me play with that

In case you were curious, my core i7 920 w/ C0 stepping is at 3.8 ghz right now, with a base clock of 200 and multiplier of 19 with hyperthreading enabled. My vcore in the bios says 1.47v, but at full load it runs at 1.43v. I barely had to touch vtt voltage, and it is at something like 1.25v (from memory, not sure exactly). Try and hit above 4ghz and post back what you reached.

P.S. Your qpi and dram voltage are different, and I think you confused the one you posted with v core. DRAM stock is generaly at 1.5 v but can safely go up to 1.65, and qpi can go up to 1.35.

 

[matt77]

nonxcarbonx

thanks ever so much for replying in so much detail. really helpful stuff. i'll give what you say a go. I've found that when i raise cpu voltage to 1.3 and above, i get unreasonable temperatures - high 80s, once 90 c on one core. I have a Cooler Master V8, which I thought would cool better than this, but maybe it isn't seated properly. Or maybe this is a common temperature for a V8. Can't find much on the net which will help me answer this.

If you had the time I'd like to ask you more about ram and why lowering it makes a more stable and overclockable system. This ram and qpi/dram settings are things I just can't get my head around. I know it sounds a ridiculous question but like I say, I am an ultra-noob. I'm also a teacher of literature so computers are not something I grew up with, but are something I find fascinating!

Thanks for the reply again - very much appreciated.

You have a really good chip to get that high on stock voltages. Just to be safe for now, lower your ram, uncore and qpi multipliers as low as they allow, so ram is probably 6, uncore 12-13(13 is better if your board allows it) and qpi of 18, just so you know those aren't bottlenecking anything. Once you get you maximum cpu freq, raise them as high as you can Don't rely on all of the auto features for dram voltage and qpi/vtt voltage.

I had to raise my voltage after about 3 ghz, so you have a really tough chip. Go ahead and raise it to 1.25-1.35 v because that is almost certainly what is holding you back and try raising your base clock again. If you don't have that high of temps (i would stop at 80-85) keep going and raise voltage/base cloock. Your safe up to 1.375 v vcore, and likely won't have any problems running up to 1.55 v. Maximum recommended vtt/qpi is 1.35 v, but that likely won't need to be raised much because of the lower multipliers. Also, go and disable turbo, speed step and virtualization, as those might get in the way. But you're almost certainly not at you maximum frequency. In fact, I think you can easily surpass 4ghz with the increase in voltage. If your still having trouble, try disabling hyperthreading, as it sucks up some voltage and produces a bit of heat. You can also raise pll voltage up to 1.88 v, but I don't know much about that because my crappy foxconn motherboard's bios doesn't let me play with that

In case you were curious, my core i7 920 w/ C0 stepping is at 3.8 ghz right now, with a base clock of 200 and multiplier of 19 with hyperthreading enabled. My vcore in the bios says 1.47v, but at full load it runs at 1.43v. I barely had to touch vtt voltage, and it is at something like 1.25v (from memory, not sure exactly). Try and hit above 4ghz and post back what you reached.

P.S. Your qpi and dram voltage are different, and I think you confused the one you posted with v core. DRAM stock is generaly at 1.5 v but can safely go up to 1.65, and qpi can go up to 1.35.

 

[nonxcarbonx]

I don't think that you need to reset your cooling because the temperatures seems pretty reasonable. If temperature continues to be an issue, just disable hyperthreading. There aren't many games that utilize more than even one thread, and four is more than enough for multitasking. If I remember correctly, I once tried operating at 4 ghz w/o hyperthreading on 1.55 v and had temperatures at about 70 degrees before I had a blue screen (they probably would have gone up more though if the cpu lasted longer).

As far as the memory goes, you get your ram frequency from the base clock multiplied by the ram multiplier. That way, if you have a base clock of 180 and a multiplier of 8, you're running it at 1440. Even though your ram is rated as 1600 mhz, it normally comes at 1066mhz and you have to change a lot of settings to get the frequency higher. It might have latencies of 7-7-7-21-1T and 1.5 volts(I don't quite understand everything behind the timings, but the rule is that lower is better performance but uses more voltage) but to run at 1600 mhz you may need 8-8-8-24-2T at 1.65 volts. When your done with your cpu overclocking, you'll be best off if you do a bit of quick research on ram overclocking and set lower timings, like 6-6-6-18-1T. That's because those latencies can actually affect performance, while the difference between 800mhz ram and 2000mhz ram boosts frames per second by something like 1-3% (I think that it's so small is because ram has a very small cache, so even though you have a high frequency the ram doesn't have enough data waiting for it when space clears up. There's a recent article on it in the memory section of the site here: http://www.tomshardware.com/reviews/memory-scaling-i7,2325.html ). You might operate at 1400mhz, but without voltage increases it's as though the ram actually is overclocked, because it has specific settings it needs to be at to run at that. Basically, you're probably best off if you use the lowest multiplier on the ram and putting it at 1.65 volts just so you know that it isn't a variable right now, and lower your latencies later. The less variables you have to deal with in the bios, the easier it is to get to your problem, which is the reasoning behind lowering all of the multipliers: only overclock one thing at a time. I'm not sure, but I think that the reason the uncore multiplier has to be twice the ram (or 2x+1 in some cases) is because that is basically the memory controller, so it has to read the ram and write the ram, and thus twice or twice +1. (If you bios allows odd number multipliers, just make it 6:13 instead of 6:12 because the bios might have set it with an error of +/- some hertz, and if it's minus I don't think your computer starts up and you have to reset everything.) I wouldn't worry about getting confused with the ram though. To this day, I can't get my 1600 mhz ram above 1400, and I think my bios misunderstands the ram's xmp (which supposedly are the settings to get the most mhz) and I just lowered my timings to 6-6-6-19-1T at 1200 mhz.

A while back I found a good post explaining the ratios. Just a heads up though: it mentions a 8:9 ratio of uncore to qpi, but don't worry about that when you're overclocking. I don't think that it's very important (and there is still a thread on this forum discussing it here: http://www.tomshardware.com/forum/forum2.php?config=tomshardwareus.inc&cat=29&post=253478&page=1&p=1&sondage=0&owntopic=1&trash=0&trash_post=0&print=0&numreponse=0&quote_only=0&new=0&nojs=0) However, I found out that apparently the qpi doesn't work past 4 ghz (not the cpu speed at 4 ghz, but the qpi's frequency) That might be important if you have a x22 multiplier for the qpi because that would mean you can't go above a base clock of 181. With the other available multiplier of x18, you can go up to a base clock of 222. The link is here, but again, don't worry about the 8:9 ratio he talks about.

http://www.xtremesystems.org/forums/showpost.php?p=3495431&postcount=877

This is Tom's Hardware's overclock:
http://www.tomshardware.com/reviews/overclock-core-i7,2268.html

X-Bit Labs':
http://www.xbitlabs.com/articles/cpu/display/core-i7-920-overclocking.html

I think bottom line is don't be afraid to mess around with it and try lots of different configurations. I personally like having a high base clock and a lower multiplier, but I've tried it dozens of ways. Every once in a while I go back into my bios and see if I can get a higher one, but it usually doesn't work. But it looks like you have a good chip so see what high you can get it.

 

[matt77]

Thanks so much for that. I understand it better now - I'll check out those articles you mention for sure.

I'll lower the RAM multiplier and try to sort out latencies later.

Thanks again.

I don't think that you need to reset your cooling because the temperatures seems pretty reasonable. If temperature continues to be an issue, just disable hyperthreading. There aren't many games that utilize more than even one thread, and four is more than enough for multitasking. If I remember correctly, I once tried operating at 4 ghz w/o hyperthreading on 1.55 v and had temperatures at about 70 degrees before I had a blue screen (they probably would have gone up more though if the cpu lasted longer).

As far as the memory goes, you get your ram frequency from the base clock multiplied by the ram multiplier. That way, if you have a base clock of 180 and a multiplier of 8, you're running it at 1440. Even though your ram is rated as 1600 mhz, it normally comes at 1066mhz and you have to change a lot of settings to get the frequency higher. It might have latencies of 7-7-7-21-1T and 1.5 volts(I don't quite understand everything behind the timings, but the rule is that lower is better performance but uses more voltage) but to run at 1600 mhz you may need 8-8-8-24-2T at 1.65 volts. When your done with your cpu overclocking, you'll be best off if you do a bit of quick research on ram overclocking and set lower timings, like 6-6-6-18-1T. That's because those latencies can actually affect performance, while the difference between 800mhz ram and 2000mhz ram boosts frames per second by something like 1-3% (I think that it's so small is because ram has a very small cache, so even though you have a high frequency the ram doesn't have enough data waiting for it when space clears up. There's a recent article on it in the memory section of the site here: http://www.tomshardware.com/reviews/memory-scaling-i7,2325.html ). You might operate at 1400mhz, but without voltage increases it's as though the ram actually is overclocked, because it has specific settings it needs to be at to run at that. Basically, you're probably best off if you use the lowest multiplier on the ram and putting it at 1.65 volts just so you know that it isn't a variable right now, and lower your latencies later. The less variables you have to deal with in the bios, the easier it is to get to your problem, which is the reasoning behind lowering all of the multipliers: only overclock one thing at a time. I'm not sure, but I think that the reason the uncore multiplier has to be twice the ram (or 2x+1 in some cases) is because that is basically the memory controller, so it has to read the ram and write the ram, and thus twice or twice +1. (If you bios allows odd number multipliers, just make it 6:13 instead of 6:12 because the bios might have set it with an error of +/- some hertz, and if it's minus I don't think your computer starts up and you have to reset everything.) I wouldn't worry about getting confused with the ram though. To this day, I can't get my 1600 mhz ram above 1400, and I think my bios misunderstands the ram's xmp (which supposedly are the settings to get the most mhz) and I just lowered my timings to 6-6-6-19-1T at 1200 mhz.

A while back I found a good post explaining the ratios. Just a heads up though: it mentions a 8:9 ratio of uncore to qpi, but don't worry about that when you're overclocking. I don't think that it's very important (and there is still a thread on this forum discussing it here: http://www.tomshardware.com/forum/forum2.php?config=tomshardwareus.inc&cat=29&post=253478&page=1&p=1&sondage=0&owntopic=1&trash=0&trash_post=0&print=0&numreponse=0&quote_only=0&new=0&nojs=0) However, I found out that apparently the qpi doesn't work past 4 ghz (not the cpu speed at 4 ghz, but the qpi's frequency) That might be important if you have a x22 multiplier for the qpi because that would mean you can't go above a base clock of 181. With the other available multiplier of x18, you can go up to a base clock of 222. The link is here, but again, don't worry about the 8:9 ratio he talks about.

http://www.xtremesystems.org/forums/showpost.php?p=3495431&postcount=877

This is Tom's Hardware's overclock:
http://www.tomshardware.com/reviews/overclock-core-i7,2268.html

X-Bit Labs':
http://www.xbitlabs.com/articles/cpu/display/core-i7-920-overclocking.html

I think bottom line is don't be afraid to mess around with it and try lots of different configurations. I personally like having a high base clock and a lower multiplier, but I've tried it dozens of ways. Every once in a while I go back into my bios and see if I can get a higher one, but it usually doesn't work. But it looks like you have a good chip so see what high you can get it.

 

[A_Real_Overclocker]

nonxcarbonx

thanks ever so much for replying in so much detail. really helpful stuff. i'll give what you say a go. I've found that when i raise cpu voltage to 1.3 and above, i get unreasonable temperatures - high 80s, once 90 c on one core. I have a Cooler Master V8, which I thought would cool better than this, but maybe it isn't seated properly. Or maybe this is a common temperature for a V8. Can't find much on the net which will help me answer this.

If you had the time I'd like to ask you more about ram and why lowering it makes a more stable and overclockable system. This ram and qpi/dram settings are things I just can't get my head around. I know it sounds a ridiculous question but like I say, I am an ultra-noob. I'm also a teacher of literature so computers are not something I grew up with, but are something I find fascinating!

Thanks for the reply again - very much appreciated.

Those Temps are COOKING your processor below is from sticky in the overclocking forum.

Scale 4: Quad
Ci7 9xx: Tcase Max 68c, Stepping C0, TDP 130W, Idle 16W<--Core i7
QX6x50: Tcase Max 65c, Stepping G0, TDP 130W, Idle 16W
QX6800: Tcase Max 65c, Stepping G0, TDP 130W, Idle 16W
QX6700: Tcase Max 65c, Stepping B3, TDP 130W, Idle 24W
QX9650: Tcase Max 64c, Stepping C1, TDP 130W, Idle 16W
QX9650: Tcase Max 64c, Stepping C0, TDP 130W, Idle 16W
QX9775: Tcase Max 63c, Stepping C0, TDP 150W, Idle 16W


-Tcase/Tjunction-
--65--/--70--70--70--70-- Hot
--60--/--65--65--65--65-- Warm
--55--/--60--60--60--60--Safe <--
--25--/--30--30--30--30-- Cool
Re-seat that cooler and don't OC till you get cooler.

 

[A_Real_Overclocker]

I don't think that you need to reset your cooling because the temperatures seems pretty reasonable. If temperature continues to be an issue, just disable hyperthreading. There aren't many games that utilize more than even one thread, and four is more than enough for multitasking. If I remember correctly, I once tried operating at 4 ghz w/o hyperthreading on 1.55 v and had temperatures at about 70 degrees before I had a blue screen (they probably would have gone up more though if the cpu lasted longer).

As far as the memory goes, you get your ram frequency from the base clock multiplied by the ram multiplier. That way, if you have a base clock of 180 and a multiplier of 8, you're running it at 1440. Even though your ram is rated as 1600 mhz, it normally comes at 1066mhz and you have to change a lot of settings to get the frequency higher. It might have latencies of 7-7-7-21-1T and 1.5 volts(I don't quite understand everything behind the timings, but the rule is that lower is better performance but uses more voltage) but to run at 1600 mhz you may need 8-8-8-24-2T at 1.65 volts. When your done with your cpu overclocking, you'll be best off if you do a bit of quick research on ram overclocking and set lower timings, like 6-6-6-18-1T. That's because those latencies can actually affect performance, while the difference between 800mhz ram and 2000mhz ram boosts frames per second by something like 1-3% (I think that it's so small is because ram has a very small cache, so even though you have a high frequency the ram doesn't have enough data waiting for it when space clears up. There's a recent article on it in the memory section of the site here: http://www.tomshardware.com/reviews/memory-scaling-i7,2325.html ). You might operate at 1400mhz, but without voltage increases it's as though the ram actually is overclocked, because it has specific settings it needs to be at to run at that. Basically, you're probably best off if you use the lowest multiplier on the ram and putting it at 1.65 volts just so you know that it isn't a variable right now, and lower your latencies later. The less variables you have to deal with in the bios, the easier it is to get to your problem, which is the reasoning behind lowering all of the multipliers: only overclock one thing at a time. I'm not sure, but I think that the reason the uncore multiplier has to be twice the ram (or 2x+1 in some cases) is because that is basically the memory controller, so it has to read the ram and write the ram, and thus twice or twice +1. (If you bios allows odd number multipliers, just make it 6:13 instead of 6:12 because the bios might have set it with an error of +/- some hertz, and if it's minus I don't think your computer starts up and you have to reset everything.) I wouldn't worry about getting confused with the ram though. To this day, I can't get my 1600 mhz ram above 1400, and I think my bios misunderstands the ram's xmp (which supposedly are the settings to get the most mhz) and I just lowered my timings to 6-6-6-19-1T at 1200 mhz.

A while back I found a good post explaining the ratios. Just a heads up though: it mentions a 8:9 ratio of uncore to qpi, but don't worry about that when you're overclocking. I don't think that it's very important (and there is still a thread on this forum discussing it here: http://www.tomshardware.com/forum/forum2.php?config=tomshardwareus.inc&cat=29&post=253478&page=1&p=1&sondage=0&owntopic=1&trash=0&trash_post=0&print=0&numreponse=0&quote_only=0&new=0&nojs=0) However, I found out that apparently the qpi doesn't work past 4 ghz (not the cpu speed at 4 ghz, but the qpi's frequency) That might be important if you have a x22 multiplier for the qpi because that would mean you can't go above a base clock of 181. With the other available multiplier of x18, you can go up to a base clock of 222. The link is here, but again, don't worry about the 8:9 ratio he talks about.

http://www.xtremesystems.org/forums/showpost.php?p=3495431&postcount=877

This is Tom's Hardware's overclock:
http://www.tomshardware.com/reviews/overclock-core-i7,2268.html

X-Bit Labs':
http://www.xbitlabs.com/articles/cpu/display/core-i7-920-overclocking.html

I think bottom line is don't be afraid to mess around with it and try lots of different configurations. I personally like having a high base clock and a lower multiplier, but I've tried it dozens of ways. Every once in a while I go back into my bios and see if I can get a higher one, but it usually doesn't work. But it looks like you have a good chip so see what high you can get it.

Look at my reply to matt77 you are way to hot on your system 70C core is HOT! from sticky on OC forum

Scale 4: Quad
Ci7 9xx: Tcase Max 68c, Stepping C0, TDP 130W, Idle 16W<--Core i7
QX6x50: Tcase Max 65c, Stepping G0, TDP 130W, Idle 16W
QX6800: Tcase Max 65c, Stepping G0, TDP 130W, Idle 16W
QX6700: Tcase Max 65c, Stepping B3, TDP 130W, Idle 24W
QX9650: Tcase Max 64c, Stepping C1, TDP 130W, Idle 16W
QX9650: Tcase Max 64c, Stepping C0, TDP 130W, Idle 16W
QX9775: Tcase Max 63c, Stepping C0, TDP 150W, Idle 16W


-Tcase/Tjunction-
--65--/--70--70--70--70-- Hot
--60--/--65--65--65--65-- Warm
--55--/--60--60--60--60--Safe <--
--25--/--30--30--30--30-- Cool

 

[matt77]

Thanks for that Real OC - I feel that 90 is too high for me, even if Intel say TJunction is 100. I will disable hyper threading - as nonxcarbon x has recommended. Is Ci7 9xx: Tcase Max 68c, Stepping C0, TDP 130W, Idle 16W<--Core i7 the one I am looking for? Are you saying that 68c is tcase max for i7? So tjunction max is around 62c? It's going to be hard for me to overclock respecably and get that kind of coolness. I'm scared about taking off the cooler master and reseating because my mate did it for me and now he's moved away!!! The thing is, when i read people's experiences in forums here and elsewhere, they have very different opinions about temperatures. Some are happy with 70 for the cores, whilst others say 90 is fine! I guess it's about how long you want your cpu to last.

Thanks for your help.

 

[matt77]

"Are you saying that 68c is tcase max for i7? So tjunction max is around 62c?" Sorry - i mean 73 c for tjunction max?

 

[nonxcarbonx]

I that we're all safe breaking temperature specs. The highest I ever saw my temperatures go was 87 degrees on full load while running prime95 and a modified Linux stress test. With that same overclock I run rosetta@home 24/7 on 100% cpu and my temps don't go above 73 degrees.

 

[matt77]

Hi

So this is where I am. HT disabled as you recommended. Brought temps down a fair bit.

I am now at 3.8, but I have had to bring my 1600 DDR3 corsair memory down to 1200 mhz, so it's not running at the rate it is designed to. Not sure why I have to reduce memory but I do. Temps are 74-76 c under full load (small fft). CPU voltage is 1.25. I think if I push it to 1.3 the temps will rise into the 80s.

Will touching the UCLK frequency and QPI link data rate give me anything extra? To be honest, I would be very happy with 3.8 if I could get my memory to run at 1600 mhz.

Any ideas?

Thanks!

I that we're all safe breaking temperature specs. The highest I ever saw my temperatures go was 87 degrees on full load while running prime95 and a modified Linux stress test. With that same overclock I run rosetta@home 24/7 on 100% cpu and my temps don't go above 73 degrees.

 

[matt77]

Oh, and I got there with 19 X 200 bclk.

 

[nonxcarbonx]

You can give your memory 1.65 volts (which won't affect cpu temperature) and change the multiplier from x6 to x8 along with the corresponding uncore multiplier and get to 1600.

 

[nonxcarbonx]

What did it overclock to?

 

[matt77]

You can give your memory 1.65 volts (which won't affect cpu temperature) and change the multiplier from x6 to x8 along with the corresponding uncore multiplier and get to 1600.

Hi. I've got it to 3.8 totally stable with decent temps (hyper threading off). Anything over, it bsods. Adding volts, it gets too hot. But this is a sizable overclock, and I notice the difference. So I'm happy. Thanks for all your help.