2 questions about new build

[no_1_dave]

1) I have the i7 4790k, it is supposed to boost to 4.4Ghz as standard but it only boosts to 4.2Ghz. Can anyone tell me why?

2) I have 2666 ram but when I go into the bios and turn on the XMP profile the pc fails to boot. This is with no other changes in the bios. How do I fix this?
I have already updated the bios to the latest one.

Ram: http://www.overclockers.co.uk/showproduct.php?prodid=MY-055-TG&groupid=701&catid=8&subcat=2429

Motherboard: http://www.overclockers.co.uk/showproduct.php?prodid=MB-270-MS&groupid=701&catid=5&subcat=2811

Other details in case needed:
PSU is 1000w Cooler master
GTX 780

 

[stulid]

It boast to 4.4Ghz when only a single thread/core is being used, then it drops off after that.

So download CPU-Z and SuperPi and run say a 1M or greater test and watch the core speed CPU-Z reports.


As for the RAM, well you can try a BIOS update to improve compatibility if you haven't already.

 

[no_1_dave]

It boast to 4.4Ghz when only a single thread/core is being used, then it drops off after that.

So download CPU-Z and SuperPi and run say a 1M or greater test and watch the core speed CPU-Z reports.


As for the RAM, well you can try a BIOS update to improve compatibility if you haven't already.

Oh I see about the boost, cheers.

I have updated the bios already and the XMP profile still doesnt allow me to boot

 

[Danny75]

If updating to latest BIOS does not fix it, try increasing the System Agent Voltage by 0.025v each time, save/exit, rinse/repeat. Don't exceed an increase of say 0.250v in total, to be safe. If it's related to that, it shouldn't take all that much anyway. The Haswells and Devil's Canyons can have a bit of trouble running RAM at high speeds like that, if the CPU is at a high-ish speed too. You can also try adding a bit more DRAM voltage, say to 1.665/1.680v. And see how that goes and what you can reduce once you have post.

 

[no_1_dave]

Still doesn't work
Might just RMA the ram seeing as though it only seems to run at 1333 anyway and I have a cheap 1333 kit lying around here doing nothing. No point me having a nice kit when I can't use it properly. Although, it must be something else I need to do? I assumed XMP was plug and play apart from simply turning it on in the bios?

There was a message when I turn it on saying something along the lines of: "MSIs extended turbo feature will be automatically enabled when I enable XMP". I have tried disabling this but it still wont boot with XMP profile enabled.

 

[stulid]

XMP is a load and forget way to get RAM operating at its tested settings.

Maybe your CPU just cant cope with RAM running that fast the memory controller is part of the CPU.

 

[Danny75]

Could have a crack at OC Genie if you haven't already, just to see what happens. Change it to activate "through BIOS", choose Gear 2, and click the button. That also sets XMP automatically as well as enabling a slight overclock. Just wonder if that might get it going, and then you can see what voltages/settings the OC Genie is using. Shot in the dark.

 

[no_1_dave]

Could have a crack at OC Genie if you haven't already, just to see what happens. Change it to activate "through BIOS", choose Gear 2, and click the button. That also sets XMP automatically as well as enabling a slight overclock. Just wonder if that might get it going, and then you can see what voltages/settings the OC Genie is using. Shot in the dark.

I have pressed the OC Genie button in bios
It has set the ram to 2400Mhz (so better, but still not XMP)
The only other thing it does it up most of the voltages slightly and puts all cores to 4.4Ghz permanently. It seems to be prime stable.

It looks like I'll have to OC this the old fashion way.
The idea of getting the 4790k and fast ram was so I didn't have to bother with overclocking. I like having an overclocked system but no longer have the interest or time to sit down and do it. Hence getting a good CPU with a turbo function and good fast ram with the press of 1 button was appealing to me.

 

[Danny75]

I have pressed the OC Genie button in bios
It has set the ram to 2400Mhz (so better, but still not XMP)
The only other thing it does it up most of the voltages slightly and puts all cores to 4.4Ghz permanently. It seems to be prime stable.

It looks like I'll have to OC this the old fashion way.
The idea of getting the 4790k and fast ram was so I didn't have to bother with overclocking. I like having an overclocked system but no longer have the interest or time to sit down and do it. Hence getting a good CPU with a turbo function and good fast ram with the press of 1 button was appealing to me.

That's interesting. On my MSI (it's a Z87 though) the OC Genie sets RAM on XMP when enabled. However, my RAM is 2400 speed, so that might be why. 2400 is basically just as fast though, and you'd probably have had to lower from 2666 anyway, if you overclocked the CPU. Some have to settle for 2133 or even 1600 in some cases, to allow for extra 100MHz' on the CPU.

I hear you though, always nice when things can run at their stated speed/timings with "one click".

It shouldn't take long to mirror the OC Genie overclock manually, though. Just make note of the two or three(?) voltage changes compared to stock and enter them, then maybe try reducing them a bit. As for the RAM, all you have to do is set frequency to 2400, DRAM v to 1.65 and enter either of these timing sets: 10, 12, 12, 31 (Command rate 2) or 11, 13, 13, 35 (Command rate 2). No need to tinker with the rest.

You could be all done and have a stable system within 10-15 minutes (all going well). If you don't want voltages at full pelt all the time, you can later change Fixed/Override to Dynamic/Adaptive/EIST/CState on/auto (don't stress test on Adaptive as with Adaptive on some tests add 0.1v to CPU etc and temps can reach 90-100C in some cases).

Alternatively, return the RAM but maybe go for a 2133 or 2400 set to have a better chance of running XMP on that system?