Today i thought i would overclock my Intel i5 750 chip. I have a MSI P55-GD65 motherboard and a titan fenrir for a cooler but want it to be stable so went for a 3.6ghz overclock. After reading CPC issue 74 they have a guide on overclocking the i5 with the same motherboard so i just copied what they done in the bios. Everything went to plan apart from the reading CPU-Z gives me. In the magazine they get a core speed of 3611.0Mhz and a x20 multiplier for some reason i get a 1625.0Mhz and a x9 multiplier although i copied the instructions properly. Any ideas on what to do? I ran the CPC media benchmarks and im lagging a few hundred points behind the scores reported in the magazine. Thanks
have you turned off SpeedStep and C1E in the BIOS, it looks like the power saving features are kicking in and de-clocking the CPU. Try reading CPU-Z when the pc is running Prime95
disable speedstep c1e as mensioned. your fan might not be connected correctly is were id start. make sure it boots at its default speed hten slowly increase your overclock banging it in at 3.6ghz isnt smart. every board and every chip overclocks diffrently even if there the same manuafacture. id look at going up in 50mhz increases at a time. Till you see this happen. Thats when you know your hitting a cealing. If its declocking its doing it cause its undervolted or overvolted. And protecting the chip from blowing up. as a general rule each level of 50mhz requires a slight vcore jump but never above 1.42 vc ( going above this isnt a smart idea and your pushing things to break ) around 1.39 should get you a 4ghz overclock if you know what your doing this isnt a general rule some take more some take less.
For some reason i just loaded my computer and looked in CPU-Z and the core speed and the multiplier were at the speed i want (3.6mhz and x20 multiplier) then after a few seconds of watching it, it started to change. The multiplier would go to x9 then x15 and all sorts with the core speed changing also. I have Turbo boost turned off so that cant be the problem. I can show you some print screens if they will help. Just had a thought could it be that i`ve pressed the motherboard overclock bottom by an accident and its messing with the speeds?
Turbo Boost and Speed Step aren't the same thing. What you're describing is exactly what speedstep does. If you want to test that, run a stress test (on all cores) and watch the CPU speed... if its speedstep it should pop up to 3.6 the moment it comes under full load.
Doesn't sound like a heat issue at all, all Intel chips do this (lower the multiplier) when they're not under load as an energy saving measure, so don't bother turning it off. What temps/voltages are you running for 3.6GHz? (Just interested as that's what mine is running at right now with the same cooler, albeit with a different motherboard).
Temps are about 40 degrees not under load and with the fenrir speed turned down. Just ran Prime95 with coretemp and CPU-Z open. Turns out Gryphon is exactly right and under full load CPU-Z read 3.6Mhz and x20 multiplier. How do i go about turning speedstep off? I just had a quick look in the bios but couldn't find anything to disable it. Also Prime95 on for about a minute the temps went straight up to 75 degrees which isn't good but i do have the Fenrir fan turned down so i don't hear it as much also with the case fans on minimum. So looks like i`ll have to change that. Edit - After what Smc8788 just said maybe its not worth me changing it then? I mean sometimes i just go on the computer for the internet and dont need the processor running at 3.6mhz so this way it will save some energy. Temps are all over the place when the computer is just on the internet the temps are 40 degrees but thats with the x9 mulitipler and lower Mhz. Im not quite sure what i`ll get when the computer is running at 3.6 not under load. I guess by volts you mean the core voltage on CPU-Z and its 1.344V. If you want to know what i changed for the overclock just say and i`ll tell you.
Yeah, don't bother turning it off. Hardcore overclockers will tell you otherwise as it can affect stability and it's just one more thing that may limit a high overclock, but it'll be fine all the way to 4GHz. Yeah, the Vcore is the main one, and I have to say that's way too high for a 3.6GHz overclock, and is probably the main reason why your temps are so high as well. Mine's running at 1.2V, which is pretty much the minimum for it to be Intel Burn Test stable (is Prime95 stable at lower volts as it's less intensive), so even if you can't get it as low as that you should be able to massively reduce it.
What would you recommend i do then? Change the CPU voltage in the bios? I have my ram voltage at 1.645 what do you think about that? If you feel your overclock is stable and better then the one i`ve done then i`ll happily change it to your setting.
If you used the rest of the voltages that were in the CPC article a few months ago, they'll be fine and you can happily decrease the Vcore a substantial amount and it will still be 100% stable. Just remember that what settings work on my system may not on yours, so you may need something like 1.21V, but I haven't heard of anyone needing much more than 1.2V to get 3.6GHz stable. As for RAM voltage, it doesn't really matter so long as it's below 1.65V, and even then I assume you've probably overclocked the IMC as well so slightly higher voltages would still be safe. I have the same RAM as well, and I think mine's running at 1.6V @1440MHz/C8, but I'd probably leave it if I were you as it's fine as it is.
Right ok thanks for the help. Next time i restart the PC i`ll go in the bios and change the CPU voltage to 1.20V and see if its stable. What would you recommend i do to make sure its stable run Prime95 for a couple of hours making sure it doesnt fail?
I'd stay if it's Prime stable for maybe 6 hours it should be fine. You could also run Intel Burn Test for maybe 10 passes or so as that's much more intensive (should only take about 10 mins).
Was just about to stress test my computer with Prime95 but some of the workers are getting errors. Got some print screens here Worker 2 Worker 3 Any ideas?
Check your Windows 7 power management settings, if you set the minimum percentage to 50% your Mulitplier will drop to a minimum of x9 on idle, then increase on demand. Set Min and Max to 100% and it will stay at whatever your Bios is set to.
i have a the exact same setup as you so i will send you a BIOS profile when i get back to my main rig. PM me your email.
