Increase voltage after OC

[rockliffe]

Hi guys, I have just increased my CPU frequency to 3.65Ghz and although the system is running stable at 75c it looks as though this is going to be the limit (disappointingly) However, I have not increased the voltage. Is this necessary if you have a stable system or should it be increased anyway? Stock voltage at the moment is 1.500v I undesrtand the i7 chips have a max of 1.65v in the bios the next voltage increase is 1.600v would this be OK to increase it by or should I leave it where it is? If I do need to increase it should it be the Dram Voltage I change? Sorry for all the questions but this is all new to me 

[Griphos]

Actually, I believe the stock core voltage on i7 chips is 1.25v.  At least it is on my 920.  You do not need to increase voltage if it is running stable.  Increasing voltage may allow you to bump up the speed a bit more and still run stable, but the down side to increasing voltage is the increased heat.  Heat increases rapidly once you move up from stock voltages, but each chip is different.  Are you checking temps on your system under load at your current settings? 

And increasing voltages isn't always a big improvement.  Sometimes the limiting factor is just the limits of the built-in North Bridge on the chip and the necessary multipliers for memory and Uncore frequencies.  There's just a wall in these chips and no matter how hard you push them with increased voltages, they aren't going to go a lot higher. 

I would think that even 1.5v isn't good for the system without serious (perhaps liquid) cooling.  I run my 920 at 3.8 stable on stock voltages (just a one increment bump in memory voltage actually) and my system runs very cool.  I've got a very good fan, though.

Be very careful about voltages.  Increasing multipliers and clock speeds at stock voltages can cause system instability (CTD, etc), but this is all easily fixed by backing down the settings without any lasting effect.  Increasing voltages can result in fried components and expensive lessons.  If you don't know what you're doing in overclocking, stick with stock voltages and wring the most speed you can out of the system until it becomes unstable and then back down one notch.  You're system will last longer that way, and you'll be just as happy at 3.75 as at 3.9, I believe.

[rockliffe]

Nicely explained Griphos, many thanks. I'll stick with what I have...

[alainneedle1]

Hi guys, I have just increased my CPU frequency to 3.65Ghz and although the system is running stable at 75c it looks as though this is going to be the limit (disappointingly) However, I have not increased the voltage. Is this necessary if you have a stable system or should it be increased anyway? Stock voltage at the moment is 1.500v I undesrtand the i7 chips have a max of 1.65v in the bios the next voltage increase is 1.600v would this be OK to increase it by or should I leave it where it is? If I do need to increase it should it be the Dram Voltage I change? Sorry for all the questions but this is all new to me 

This is a typo, there is no way your i7 950 run at 1.5v right now....here is the min. and max. (under Intel spec) for your chip...  0.800V-1.375V

You are probably talking about your memory voltage....

CPU @3.65GHz with temp at 75C?? is this idle or under stress? Do you have a after market CPU cooler?

[rockliffe]

Hi Alain, sure no doubt you are correct about the voltage! Sure, the CPU is running at 75c under 100% stress using Prime 95 and Core temp for checking temps. During FSX it runs at about 65c. I fitted a Hyper 212 plus cooler yesterday... what are your thoughts?

[alainneedle1]

If you want to overclock a little more that's ok if you stay below 75C on all core, like Griphos said you may have to raise the voltage a little so keep an eye on the temp, Prime95 is a good stress test buy I've never used it cause IMHO it put to much stress on a system, to me Prime95 is for bragging rights....use OCCT for one hour...if you pass your OK, as I said keep an eye on the temp.

You CPU cooler is OK for the money.

http://www.ocbase.com/perestroika_en/index.php?Download

[rockliffe]

Hi Alain, sorry to be thick, but what is OCCT?

[alainneedle1]

Hi Alain, sorry to be thick, but what is OCCT?

It's a stress test software...

[rockliffe]

Cheers Alain, I'll follow yuor advice and download it immediately.

[alainneedle1]

Cheers Alain, I'll follow yuor advice and download it immediately.

Don't change anything on the test, just start the CPU test at auto medium data set and normal, hyperthreading unchecked....

[rockliffe]

Thanks Alain, I've got the program, I'll run it first thing tomorrow, thanks...

[rockliffe]

Hi Alian, i've run the test and got the PC up to 3.65Ghz for an hour at 75c. it all seemed stable until I rebooted and then there was an error message saying that due to an overclock or voltage change that the computer could not boot, so I have taken it back to 3.5Ghz. i'm now seeing what the outcome will be...

[Heiko Glatthorn]

Which mainboard and RAM do you have exactly ?

[rockliffe]

Hi Heiko, I have the Gigabyte GA-EX58-UD3R motherboard and 3 sticks of DDR3 2Gb Kingston RAM (matching) I ran FSX yesterday and I have to admit although it ran a little faster it in no way ran as fast as I would have expected. I seem to have a real issue with images loading. For example, if I change from external view to VC it takes about a second to load the textures for the instruments (Lancair) also I notice when moving to an external view the landscape can take several seconds to load.  This was the main reason behind why I want to OC. Yesterday while flying in GEX Europe, there was a massive white area which appeared across the landscape and only disappeared after minimizing the screen and them maximising it again. I have been plagued with lack of smoothness ever since going to Win 7. There's the irony!  I try to read up on overclocking but to be absolutely honest, it goes above my head. \ I need to find out whether I should be doing something else in BIOS other than just increasing the CPU frequency. On one hand I read about increasing all sorts of other elements like front side bus and RAM freaquency??? and then I read about OC the i7 is very simple and all I have to do is increase the CPU Host frequency and everything else adjusts itself automatically (?)  Is this so or do I need to adjust some other element?

[Griphos]

Hmmmm, you shouldn't be getting that image loading behavior even at stock speed on your system.  I'm thinking something else is the culprit, and it might be memory related.  What are you running in the background when you run FSX?  Anyway, I don't think OC is the answer to this issue. 

[rockliffe]

Hi Griphos, sure, I've been thinking this all the while.  It's got a to a point where I'm spending most of my time trying to get to the bottom of this issue rather than just enjoying my flying. If I can summarise:- I recently had the guys who built the computer run a whole load of benchmark tests on the system to check if there were any hardware problems. They said everything was as it should be. They also installed Win 7 64bit, all the latest drivers etc, installed a separate HD purely for FSX. I then installed the GTX 470.  I reinstalled FSX over three days. Install, reboot, and defrag between each install. It's difficult for me because although I have more than a basic knowledge of PC's, nevertheless, I'm not really experienced like many of you guys on the forum, I simply love flying! Running in the backgraound? well, apart from the basic W7 progs, nothing. I don't have any antivirus running... it's really frustrating...

[Heiko Glatthorn]

Oh right, i have the same mainboard - extremely easy to overclock 

If it won't move to 4 GHz (or above) there is most likely an issue with your RAM settings. Temps are o.k., right ?

I left everything on auto except the RAM voltage and RAM multiplier (auto settings using the correct timings, which is a first...) - just raised the FSB.

So do you have 1333 MHz or 1600 MHz RAM ?

[rockliffe]

Hi Heiko, thanks for your input. Sure, I have not changed anything else except the CPU frequency with the OC. As for RAM, I have three sticks of Kingston 2Gb as for 1333Mhz or 1600Mhz (?) sorry, As for info from the BIOS screen:- The CPU OC is 3.40 Ghz with a slight voltage increase to 1.24374v  The base memory is 640k, the external memory 6142M and Total memory 4144M The memory frequency (there are two side by side) the one on the left reads 1066 the other 1184 (?)  I have captured the settings which I hope you might find helpful. God knows, I really need to get to the bottom of this. Your help is very much appreciated 

[Heiko Glatthorn]

Ah right, there is your problem. Those are standard 1333 MHz RAM. You are getting to 3.6 or 3.8 GHz max with those, correct ? This intelligent tweaker does actually an amazing job by itself to get there... If you want to reach 4+ GHz you'll need 1600 MHz RAM (or faster).

FSB 200 at 2:8 FSB/DRAM ratio is 1600 MHz for the RAM. Not sure about the i950 multiplier. Is it 20 ? 200x20 would be 4 GHz on the CPU.

[rockliffe]

Ah, OK... many thanks Heiko. I understand what you are saying, but would I expect the kind of behaviour I am experiencing with the setup I have? My motherboard only shows support for DDR3 2000+/1333/1066/800 MHz memory modules... does this mean I cannot use 1600?

[Griphos]

Yes, you're running old and slow memory.  I'll leave it to Heiko to answer whether this mb can handle 1600+ memory (I suspect it can).  But I also see from your pics that you're running your CPU at 1.8 GHz with multiplier of 12x at the time you ran CPU-Z.  This could be because you left something like Turbo or SpeedStep setting enabled in BIOS such that the CPU is downclocked when not under load.  But, if you have actually set the multiplier at x12, then you have seriously underclocked this CPU.  I suspect the former, and you might want to disable that feature in BIOS.  You're also showing a FSB speed of 148.  That's low.  As Heiko said, a 20x multiplier at 200MHz will yield 4.0 GHz clock speed.  With your chip, you should be able to go to at least 180 or 190 MHz with a 20x mulitiplier with stock voltages no problem.

You're also showing a somewhat lower Core voltage than you think, although somewhat higher than the 1.2v I think is standard on this chip/mb. 

Another issue appears to be your DRAM (NB) multipliers and QPI multiplier.  I believe the i5 is made to go as low as 16x on the QPI.  Your QPI is at 18x.  This is fine, just limits your OC headroom.  If you want to go to 4.0 or higher, I'd set the QPI multiplier at 16x.  This also allows more headroom for memory, which has to be set at specific multiples of FSB and QPI. 

I'm no expert.  Just a rank amateur at overclocking.  But these things are what jump out at me.  I still think you've got a memory problem, and the readings you offer below further confirm that for me. 

[rockliffe]

Hi Griphos, thanks for the advice. Yes, the CPU has turbo enabled. I will set it to normal immediately... done! Forgive me Griphos, by now you have probably guessed that I am learning.... so, apart from thre RAM issue, what would you suggest my next step should be.... upping the FSB speed?

[Griphos]

What have you set the multiplier at?  And what have you set the Bclk speed to (in MHz)? 

[rockliffe]

Hi Griphos, BCLK frequency is 150 and it automatically changes the CPU frequency which is 3.45ghz I haven't changed anything else othe rthan increasing the V core voltage by one click, up from 1.23750v to 1.24375v The system memory mutiplier is set to auto...  As a matter of interest should I be increasing the RAM or is this done automatically?

[Griphos]

I need to know the CPU multiplier.  If your bus speed is 150 and you think you are at 3.45, then the multiplier must be 23x.  I think you would get better performance by setting the bus speed to 180 and the multiplier to 20x for 3.6GHz.  Then you could bump the bus speed by 10 MHz increments and test stability in between until you got as high as you could go.  Increase to instability and then back down 10 MHz. 

I don't think you can increase the speed of your RAM without getting better(faster) RAM. 

[rockliffe]

Hi Griphos, thanks for your help. I found the multiplier which was set at 23x. I followed your advice and set BUS speed to 180, the multiplier to 20x and moved the CPU frequency to 3.6Ghz. I kept the Vcore Voltage at 1.24375. I ran OCCT for an hour, all the tests were passed. Temps for the cores were 1) max 63  2) max 59  3) max 58  4) max 58  the voltage seemed to move  between 1.18 -1.20 so unsure whether I should decrease my voltage back down to 1.2375v  After these changes the big difference was the temperature, before, with the previous settings (obviously incorrect) I could only get to about 3.55Ghz with temperatures of 75c. However, after getting quite excited having done the tests, I ran FSX and was faced with absolutely no change whatsoever  :'(  I have to admit at being very frustrated. My FSX experience is being overshadowed with more time being spent on trying to get the darn thing to function correctly rather than actually flying!    I have attached a picture to explain the actual problems I am having. I have been told that it appears to be a memory issue, that textures are just not loading quickly enough. this is not due to any incorrect OC, it's the OC that I have initiated to try and get rid of this problem. When I change a view, the image can take a couple of seconds to appear. For example in an aircraft, the instruments will take 1-2 seconds to appear. Clouds and ground textures have the same problem. Often there will be large areas of black... yesterday I tried an interesting experiment.... I moved the sliders on the right, Autogen and scenery complexity to zero and all other sliders to 50%. I then locked the framerate to 15 and flew a default aircarft. The result was EXACTLY the same, a delay in loading textures when returning to a new view...!! \  So I ask, can it be memory if so resources are being freed up by these low settings?

[Griphos]

Hello,

Yes, as I've said a couple of times, I really do think this is a memory load issue, and I think the memory you have in your system is at it's maximum effectiveness.  In fact, this seems more like a problem associated with too little memory rather than too slow memory.  There could also be problems or damage to your modules.  Or there could be problems with how the OS is managing memory.  All of this is extremely difficult to diagnose from a distance, as I'm sure you know.  If this were a more common problem, then there would be more well known responses.  I certainly understand your frustration. 

But I wasn't suggesting the OC changes to fix this problem, just to fix your OC situation.  I haven't ever thought, as I've said, that these sorts of problems are caused by inadequate CPU speed. 

Again, I'm no expert.  I think my next step would be changing out the memory for better, faster memory.  Something like this is not too expensive an upgrade:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820145224

Getting memory rated for 2000MHz would be even better.

But if there were some way to test how your system is using memory that I don't know about, that would be ideal.  Perhaps someone else has more knowledge here and would have some suggestions.  I also worry that this could be an issue caused by the interface of your memory and your GPU. 

Wish I could be of more help.

[rockliffe]

Hi Griphos, many thanks for your help and input with this, it is very much appreciated. I understand what you are saying and like you said, it could be one of a number of things. I guess I am hoping someone would come along and know exactly what the problem is.... your help is very much appreciated...

[alainneedle1]

Hi Heiko, thanks for your input. Sure, I have not changed anything else except the CPU frequency with the OC. As for RAM, I have three sticks of Kingston 2Gb as for 1333Mhz or 1600Mhz (?) sorry, As for info from the BIOS screen:- The CPU OC is 3.40 Ghz with a slight voltage increase to 1.24374v  The base memory is 640k, the external memory 6142M and Total memory 4144M The memory frequency (there are two side by side) the one on the left reads 1066 the other 1184 (?)  I have captured the settings which I hope you might find helpful. God knows, I really need to get to the bottom of this. Your help is very much appreciated 

First of the NB number are wrong, the exact number should be 2368.4 (4 x 592.1 = 2368.4)

Second, in bios.... disable everything like Speedstep and what ever will downclock your CPU when ideling....if you look at the CPU speed 1776.3GHz is telling me you have not disable Speedstep, also disable Hyperthreading if enable.....

Bus speed at 200 is ok BUT you will need more core voltage and more QPI/VTT voltage to be stable...it's a hit and miss type of settings....you also may need to raise the rams voltage a little over 1.50v....try the next value after 1.50v but don't go crazy on that....1600MHz rams will definitly bet better.... 3 x 2GB at 1600MHz with a tight timing...

Try only one thing and see, so first thing first get your NB to the right speed and test, if you need to make any adjutment be sure to adjust one thing only and test...do not change 2 or 3 thing cause you will not know what's working and what's not (very time consuming)....

Last thing...make sure you have enter all settings in your bios by hand....auto does not work if you want a good overclock...good luck.

Finaly been stable with OCCT does not mean you'll be stable with FSX.....this simulator is that funny.

[rockliffe]

Hi Alain, many thanks.... sure, I have unchecked the turbo boost that had been on and also Hyperthreading. Since posting the CPU-Z screenshots I have changed the mulitplier and set the bus speed to 180, the multiplier to 20x and moved the CPU frequency to 3.6Ghz. So I will check the NB frequency and change it accordingly Alain... thanks...

[alainneedle1]

If you have disable speedstep and everything who can downclock your CPU when at idle your CPU-Z reading on the CPU should be the same as you have it in bios....3.6GHz...

[Heiko Glatthorn]

Alain, Speedstep works on the UD3R even with 4,2 GHz - no negative impact at all as far as i can see. It's not a mistake when the CPU idles low instead of humming that high for nothing.

But o.k. it would also be no mistake to establish the o/c first with Speedstep off and then enabling it afterward. This way you know right away why it doesn't work anymore  .

[alainneedle1]

Alain, Speedstep works on the UD3R even with 4,2 GHz - no negative impact at all as far as i can see. It's not a mistake when the CPU idles low instead of humming that high for nothing.

But o.k. it would also be no mistake to establish the o/c first with Speedstep off and then enabling it afterward. This way you know right away why it doesn't work anymore  .

.....the purpose of having Speedsteep disable when overclocking is to not have any power fluctuation when stress testing, as you know (to take OCCT for exem.) the software will load the CPU to the max down to 80% and up to 100% again and so on until the test is done, that is why you need to be sure your CPU is having max power on hand all the time, it will be a lot faster and easier to find a stable OC....

What you are looking for when searching for a stable overclock is to take all the speculation out of the equation so by doing so (disabling speedstep) you have one thing less to worry about...after your rig is stable you can try again with speedsteep enable........ ................

[rockliffe]

Thanks Alain, sure I understand. the system appears pretty stable over the last 24 hours, working Photoshop and FSX so I will up the OC to 3.7Ghz next I think... temps seem massively better since getting the correct multiplier numbers and the correct settings...

[Griphos]

Actually, I think the reason for disabling it during testing, which you should do, is that some (most?) of these BIOS "turbo" features allow the CPU not only to step down under lessened loads, but to actually increase bus speed and multiplier (depending on the BIOS) and sometimes even voltage above the settings you select, so that under extreme load, you quite likely will be raising the speed of your system above what it can at all handle as you try to sneak up on maximum settings. 

I think this is a good reason for keeping it off as well once you have pushed your machine to the limit. 

And the next step in oc for you, Rock, would be 3.8GHz (190x multiplier at 200MHz bus speed). 

[rockliffe]

Got it, thanks a lot...

[alainneedle1]

Got it, thanks a lot...

Are you stable @ 3.7GHz now?

[rockliffe]

Hey, it looks like I'm stable at 3.8Ghx Alain! Just finished my second pass (2 hours) with OCCT max temp of 65c! Voltage steady at 1.18-1.2v Tell me Alain, why is it that number one core shows 65c while the other three average at about 61c?

[alainneedle1]

It's normal, don't worrie about it.

[rockliffe]

Cool... 3.9Ghz tomorrow all being well!