Quick question on i5-750

[sgt bombulous]

A while back I had a little bit of a scare while I was overclocking (or trying to overclock) my i5-750. I believe I used the XMP profile, which was probably a mistake. I was thinking of trying again, and after looking at the manual profile, it seems like it might be a lot easier than it sounds.

I have to throw in this disclaimer first... I do NOT plan to do some epic overclocking to 4.0 GHz or anything, I'd be ecstatic to get it to 3.0 GHz and have it run stable, which is apparently very easy. So the question: Can I simply change the profile to manual and adjust the BCLK Frequency upwards a little bit? I figure adjusting it to 150 would get me to 3.0 GHz. I wouldn't have to mess around with voltages for such a modest increase, would I?

My system is:

CPU: Intel i5-750
Motherboard: ASUS P7P-55D Pro
Video Card: eVGA GTX 460 1GB
RAM: Corsair XMS3-1600, 8 GB
OS Drive: Intel X25M, 80GB
Data Drive: Samsung HD103SJ
PSU: Antec Earthwatts 650
OS: Windows 7 Pro x64

System runs great now so I might not even bother, but I was just curious in any event.

Thanks!

 

[skater44surf]

ok sgt i know this might sound a little funny but just roll with it, go to my post http://www.tomshardware.com/forum/261071-29-intel-core-4ghz-temps-voltages-correct
and read there its about 35 or so posts on overclocking my i5 750, i got it to 4ghz easily, 3.6ghz etc, it might answer some of ur questions, i also have screenshots on there that might help u out, check it out!

 

[sgt bombulous]

ok sgt i know this might sound a little funny but just roll with it, go to my post http://www.tomshardware.com/forum/261071-29-intel-core-4ghz-temps-voltages-correct
and read there its about 35 or so posts on overclocking my i5 750, i got it to 4ghz easily, 3.6ghz etc, it might answer some of ur questions, i also have screenshots on there that might help u out, check it out!

I saw that... But all I want to do is overclock it a little.... I don't want to mess with CPU voltages, or RAM timings, or any of that. I guess I'll add a few questions to further expose my ignorance here (woo hoo!!!)

1) Does overclocking have to be done in the bios? I opened up the ASUS Turbo Evo program, and it had an option for messing with the BCLK, but it didn't seem to do anything.
2) If you do it in the bios, which profile do you use? This might be useful for me since we both seem to have a similar motherboard.
3) Can you do it with just changing BCLK and leaving the multiplier alone?

Thanks again

 

[sgt bombulous]

Actually it appears that Turbo Evo does work... I increased the BCLK to 150 in Turbo Evo and ran CPU-Z and it appears that the BCLK adjustment took. Why doesn't this show up anywhere else (IE, "My Computer" etc...)? It's obvious it worked since my SuperPi calc to 1M went from 14 seconds to 13 seconds... So is this it? I'm running at 3.0 GHz?

 

[wolfram23]

I have the same CPU and mobo as you bombulous...

I found that I could get up to about 165 or even 170 base clock with the voltages on auto. Not that I like it, but it did work. Your mobo will show the "current voltage" values. IMO, set it to auto, save the BIOS and exit, then go back into BIOS when it reboots. See what the voltages say for VTT and Vcore. These are a good starting place, and if you can, start by reducing VTT a little then Vcore a little (like 0.00625 or 0.0125V) and each time you make a change try running Intel Burn Test to see your temps and of course check stability (5-10 runs on High stress).

You should make the adjustment in the BIOS not Turbo Evo... I mean it works, but there's not much point and it can potentially be bad if the program screws up. Plus it's using system resources that otherwise can be free.

But yeah, 150 base clock is nice and easy, but your 1600mhz RAM will be slower than it needs to be.

 

[lothdk]

A while back I had a little bit of a scare while I was overclocking (or trying to overclock) my i5-750. I believe I used the XMP profile, which was probably a mistake.

All your other questions seems to have been answered, so I just wanted to add to this you said in your first post.

All enabling XMP profile does, is making the correct (max) settings for your memory, including voltage. You have to set the BCLK yourself to overclock the CPU, XMP is memory only, and really is just an automatic way of entering the settings that you yourself should enter anyway.

 

[sgt bombulous]

Perhaps I should recap what happened the first time so that I can give the crowd some justification as to why I'm a little reluctant... Back in February I decided to have a go at this business... So I set the OC profile to XMP and rebooted - No problems, RAM running at 1600 MHz etc... Then I decided to mess with the BCLK a little bit. To be honest, I don't think it went much above 140. When I restarted, the PC took a LONG time... I thought it was stuck, so I shut it off. When it restarted it said "Overclock failed" and I think gave me the option to return bios to defaults, which I elected to do. On a subsequent restart, it advised me it could not find the default boot device, and on yet another restart, it wouldn't even POST... It just sat there, but the PCI LED error light was on.

One of my theories at the time was that I has accidentally adjusted the PCI frequency instead of the BCLK, but this doesn't see like something that would be easy to mess up. I ended up calling a local store and they said I might try resetting the motherboard by removing the CMOS battery. I did this, and then I could at least get back into the bios, however I still had the boot disk error. As a final ditch effort, I unplugged the Samsung drive (Drive D, data storage only). At the time I had a Seagate 250 GB drive for the boot, not the SSD. In any event, this to did it, I then got a normal restart. Obviously I still want to use my data drive... So I moved it to another SATA port, and everything has worked fine. EXCEPT, after getting the new arrangement working again with the SSD, one time I did get the aforementioned boot device error. Moving the Data drive yet again remedied this, and it has endured 30+ restarts without a hitch.

So as you can see... I've had kind of a rough ride with this. If anyone has any ideas as to what caused the menagerie of symptoms above I'd love to hear it. I'm just scared that going into the bios and messing with anything at all will lead me down another, unpleasant road.

Thanks!

 

[wolfram23]

Well that's a bit odd, but at least it's not RAM/CPU/mobo issues, it's the boot drive. Could be bad timing and it's starting to die...

Anway, just FYI, to achieve 1600mhz RAM the base clock can not be any lower than 160, which means your CPU speed went up 20%. 160x10=1600mhz RAM. The next base clock to set the RAM at that speed is 200, which is what I use to achieve 4ghz no turbo.

If you start to mess with the base clock, chances are you increased it a bit and caused the RAM to get unstable, let's say you set it to 168 that means the RAM is at 1680, which might be too high to run at CL8 so it causes boot issues.

On the other hand, you say you don't think the base clock got above 140. If you had XMP enabled at this time, that's impossible, so either you adjusted the PCIe frequency from 100->140, or you lowered the base clock from the 160 set by XMP. PCIe frequency can cause slight issues but none that you can't recover from. I tested up to 130mhz PCIe and still booted and ran tests on my GPUs, I found it gained 1% FPS across all benchmarks. However, subsequent boots at that frequency had issues resulting in no audio, no internet connection, or simply blank screen boots. If you get the "overclock failed" screen, simply go back into the BIOS and change things. I now run PCIe at 110mhz and it's causing zero issues (it's been a few weeks).

Nothing in overclocking a CPU should be able to harm a boot drive. I just can't see how that's even possible.

What I think happened is that when you reset to default, it selected your primary boot drive as your storage drive. You need to make sure the Boot order selects your boot drive first. Usually having the Boot drive in SATA port 1 is a good idea (if they're stacked ports, you might have had 1 and 2 mixed up).

 

[sgt bombulous]

Well that's a bit odd, but at least it's not RAM/CPU/mobo issues, it's the boot drive. Could be bad timing and it's starting to die...

Anway, just FYI, to achieve 1600mhz RAM the base clock can not be any lower than 160, which means your CPU speed went up 20%. 160x10=1600mhz RAM. The next base clock to set the RAM at that speed is 200, which is what I use to achieve 4ghz no turbo.

If you start to mess with the base clock, chances are you increased it a bit and caused the RAM to get unstable, let's say you set it to 168 that means the RAM is at 1680, which might be too high to run at CL8 so it causes boot issues.

On the other hand, you say you don't think the base clock got above 140. If you had XMP enabled at this time, that's impossible, so either you adjusted the PCIe frequency from 100->140, or you lowered the base clock from the 160 set by XMP. PCIe frequency can cause slight issues but none that you can't recover from. I tested up to 130mhz PCIe and still booted and ran tests on my GPUs, I found it gained 1% FPS across all benchmarks. However, subsequent boots at that frequency had issues resulting in no audio, no internet connection, or simply blank screen boots. If you get the "overclock failed" screen, simply go back into the BIOS and change things. I now run PCIe at 110mhz and it's causing zero issues (it's been a few weeks).

Nothing in overclocking a CPU should be able to harm a boot drive. I just can't see how that's even possible.

What I think happened is that when you reset to default, it selected your primary boot drive as your storage drive. You need to make sure the Boot order selects your boot drive first. Usually having the Boot drive in SATA port 1 is a good idea (if they're stacked ports, you might have had 1 and 2 mixed up).

Are you using your JMicron port? No matter what I did, I couldn't get it to work properly with the SSD (I was getting very slow read speeds and the Intel SSD toolbox wouldn't work). I finally just ended up disabling the controller altogether and running it on one of the other ports. Not sure if there's a way to get it and the SSD to play nice, but I wasn't able to find it. Just a word of warning if you decide to try one out.

I'm pretty sure the SSD is NOT in SATA 1 at the moment. Why they had to go and assign the angle ports as 1-4 I'll never know... I'm using left angle SATA cables and running my optical drive from them at the moment, the boot drive is in 5 or 6. If I just shuffle the SATA ports around and then reboot, this won't change anything in the system configuration will it? All SATA ports are running in AHCI.

The other thing is my time to POST... It takes almost 20 seconds from hitting the power button to get to the windows boot screen, then it only take 12 seconds or so to the desktop. Could something be wrong with my RAM? I ran a memory test on the 1st 4 GB, but since it only runs 4 at a time I guess I should swap them out and run in batches? Sorry for all of the questions... The computer runs perfectly, just some small quirky things I guess.

Thanks!

 

[wolfram23]

I don't use JMicron. I just have a RAID 0 set up, which is supported by my mobo so I don't have any extra software or drivers installed for it either... pretty much plug and play (after a quick set up).
I also haven't used an SSD, so not sure what kind of issues you're having with that. Regardless, you should be able to select it in the boot menu, right? Like in the BIOS there's a place to select the boot order, so if you select the SSD as 1st (or 2nd, after optical) it should boot from that.
As for the long POST time, has it always been 20 seconds? Probably a mobo limitation than any RAM/CPU/HDD/SSD issue. I haven't really timed mine but 20 seconds sounds about right. At least you don't have the 15 second delay until it starts to POST lol.

 

[sgt bombulous]

I don't use JMicron. I just have a RAID 0 set up, which is supported by my mobo so I don't have any extra software or drivers installed for it either... pretty much plug and play (after a quick set up).
I also haven't used an SSD, so not sure what kind of issues you're having with that. Regardless, you should be able to select it in the boot menu, right? Like in the BIOS there's a place to select the boot order, so if you select the SSD as 1st (or 2nd, after optical) it should boot from that.
As for the long POST time, has it always been 20 seconds? Probably a mobo limitation than any RAM/CPU/HDD/SSD issue. I haven't really timed mine but 20 seconds sounds about right. At least you don't have the 15 second delay until it starts to POST lol.

Ok, so here's where we are now... I decided to take the plunge. I first went in and set the OC profile to manual, and then restarted. This alone seemed to take a little bit of time off of the time to POAST. Then I restarted again and set the BCLK to 140, exited, saved, no problems. Restarted yet another time and set to 150, and it worked fine. Some things I'm wondering though:

1) Can you remind me of the relationship between BCLK and Memory Frequency? My memory is now running at about 1500 MHz (749.something x 2). It's obviously increasing with BCLK since it should be running at 667/1333 normally.
2) Multiplier seems stuck at 21... Any time I run apps which use the CPU heavily (I ran Superpi to 4M, for instance), multiplier is locked at 21 and overall frequency is about 3150 MHz (which makes perfect sense). But shouldn't the multiplier be defaulted to 20 for this processor?

Finally, the SSD is working perfectly now. Disabling the JMicron was the key to getting it to work nicely. I read somewhere else that JMicron hasn't developed driver for the JMB363 that runs SSD's properly... Which is weird because I think they actually make SSD controllers for other companies (not for Intel, obviously). For boot priorities I have EVERYTHING disabled except the SSD. If I need to boot from an optical drive I'll just reenable it.

Thanks for your help! I'll pick your response to this as the best.

 

[wolfram23]

Yeah no problem!

RAM: Your ram is multiplied by the base clock. This whole system is new with the Intel Core i series, deviating from the previous standard of Front Side Bus and ratios (FSB:RAM).
What this means is that you have your base clock, a CPU multiplier, a RAM multiplier, and a QPI multiplier. These multipliers are generally locked although the "K" series are unlocked.
Your options for multipliers are:
9-21x CPU multipliers
6, 8, 10x RAM multipliers
34, 36x QPI multipliers

You'll notice that the RAM doesn't show multipliers, but if you select the speed there's 3 options that correspond to 6/8/10x. 1500 is probably not optimal speed. For example 1600mhz RAM CL8 might be able to only get as high as 1640mhz on CL8, and at 1650mhz CL8 will crash. So from, say, 1650-1800 you need CL9. Goes the other way too, 1500mhz you might need CL8 which we know works up to 1640mhz so in essence you have 140mhz of waste on the RAM. (the upshot is that RAM barely makes a noticeable speed difference)

As for the CPU speed and multiplier. Under around 175 base clock you can still use turbo boost. This means that while your base CPU multiplier is technically 20x, it's actually going to use 21x for 4 core/thread situations. From there it goes up, to a max of 24x multiplier on a single core/thread. Turbo boost is a great feature and really improves efficiency but I found that for me the reasonable limit was 175 base clock (1.31Vcore 1.21VTT) giving 3.68ghz -> 4.2ghz and my RAM I ran at 1400mhz CL7. Now, however, I'm running 200x20 4ghz no turbo (1.32 Vcore 1.24 VTT) and 1600mhz CL8 RAM. The turbo OC has much lower temps, but currently I prefer the 4ghz OC.

 

[sgt bombulous]

Best answer selected by sgt bombulous.

 

[sgt bombulous]

Yeah no problem!

RAM: Your ram is multiplied by the base clock. This whole system is new with the Intel Core i series, deviating from the previous standard of Front Side Bus and ratios (FSB:RAM).
What this means is that you have your base clock, a CPU multiplier, a RAM multiplier, and a QPI multiplier. These multipliers are generally locked although the "K" series are unlocked.
Your options for multipliers are:
9-21x CPU multipliers
6, 8, 10x RAM multipliers
34, 36x QPI multipliers

You'll notice that the RAM doesn't show multipliers, but if you select the speed there's 3 options that correspond to 6/8/10x. 1500 is probably not optimal speed. For example 1600mhz RAM CL8 might be able to only get as high as 1640mhz on CL8, and at 1650mhz CL8 will crash. So from, say, 1650-1800 you need CL9. Goes the other way too, 1500mhz you might need CL8 which we know works up to 1640mhz so in essence you have 140mhz of waste on the RAM. (the upshot is that RAM barely makes a noticeable speed difference)

As for the CPU speed and multiplier. Under around 175 base clock you can still use turbo boost. This means that while your base CPU multiplier is technically 20x, it's actually going to use 21x for 4 core/thread situations. From there it goes up, to a max of 24x multiplier on a single core/thread. Turbo boost is a great feature and really improves efficiency but I found that for me the reasonable limit was 175 base clock (1.31Vcore 1.21VTT) giving 3.68ghz -> 4.2ghz and my RAM I ran at 1400mhz CL7. Now, however, I'm running 200x20 4ghz no turbo (1.32 Vcore 1.24 VTT) and 1600mhz CL8 RAM. The turbo OC has much lower temps, but currently I prefer the 4ghz OC.

If I increase BCLK to 160, the RAM will run at 1600 MHz with a 10x multiplier, right? This would also result in a non-turbo'd freq of 3200 MHz, which still sounds extremely reasonable for this. I should be able to easily go for 160 BCLK without changing anything, no? And by 1500 MHz being not ideal, you just mean that it could just as well be 1600, not that there is any real detriment for having it set at 1500 right?

 

[wolfram23]

^ that's right on all accounts. Although IMO after setting auto voltages, it can be worthwhile to try lowering from what auto sets it to in order to get better temps. Also make sure you test the OC out for stability.

 

[sgt bombulous]

^ that's right on all accounts. Although IMO after setting auto voltages, it can be worthwhile to try lowering from what auto sets it to in order to get better temps. Also make sure you test the OC out for stability.

What's the best way to test the OC? I'd prefer something that's free if at all possible...

 

[wolfram23]

Run 10 passes of Intel Burn Test on High stress, and run Real Temp as well to make sure your temps are ok. A lot of people also recommend up to 10 or 12 hours of Prime 95.

You never mentioned it, but I hope you have aftermarket cooling. You can't go this high on stock fan. Temps should be below 70 for sure. The Tj max from Intel is 72.5C... IMO in a burn test up to 75-78C is ok, but only because normal usage is never that high.

 

[sgt bombulous]

Run 10 passes of Intel Burn Test on High stress, and run Real Temp as well to make sure your temps are ok. A lot of people also recommend up to 10 or 12 hours of Prime 95.

You never mentioned it, but I hope you have aftermarket cooling. You can't go this high on stock fan. Temps should be below 70 for sure. The Tj max from Intel is 72.5C... IMO in a burn test up to 75-78C is ok, but only because normal usage is never that high.

Actually all I have is the dinky lil' thing it came with... Do you think I'm even ok to run it at 150 BCLK on stock? This doesn't seem like that much of a jump... And 160 would probably be the highest I'd EVER go.

 

[wolfram23]

I don't know, test it. I never put the stock cooler on mine.

But it would definitely be worthwhile to spend $30 or $40 on a cooler. Hyper 212+ is a good cheaper one.

 

[sgt bombulous]

I don't know, test it. I never put the stock cooler on mine.

But it would definitely be worthwhile to spend $30 or $40 on a cooler. Hyper 212+ is a good cheaper one.

That looks like a good one... Do I have to remove the Motherboard in order to install it? it's something I can do, but I just REALLY don't relish the thought of... Every time I take a motherboard out I'm always terrified I'm going to zap it with the slightest touch...

 

[sgt bombulous]

Nevermind, I read the review on canucks and it's installation looks pretty straighforward. Thanks for all your help!

 

[wolfram23]

Cool!

(Some coolers need a back plate installed, but the plus side is that some cases have an opening so you can get at it, so really, it depends)

 

[sgt bombulous]

Cool!

(Some coolers need a back plate installed, but the plus side is that some cases have an opening so you can get at it, so really, it depends)

Update - I have it running at BCLK 160, RAM at 1600 MHz. Also bought and installed Hyper 212+. I like this thing... Removing my motherboard gave me an opportunity to clean up my cables a bit anyway. Here's a pic.

Ran Intel burn test, 10 iterations on very high stress, highest temp was 73 C. Keep in mind my room is VERY hot. I ran 5 iterations on max stress later that night and the temps didn't even break above 70 C.