Does XMP disable 1156 Turbo?

[ekoostik]

Has anyone else noticed a problem where XMP turns off Turbo mode with the Lynnfield chips - specifically the i7 860 in a Gigabyte GA-P55M-UD2? I had been noticing some odd behavior but haven't been able to find confirmation elsewhere on the net.

Basically, I noticed that my 860 was always running at x22, maybe x21, but never lower or higher. I ran Prime95 on 1 thread and it stayed at x22. The only real change I had made to BIOS was to turn on XMP. (I had done a couple other small things, disable floppy drive, set 5-SEC OFF enabled, etc.)

So I turned off XMP. This time when I booted up the multiple was showing as x9. First sign of Turbo working. So I launched Prime 95 on 1 thread and the multiplier shot up to x26.

I'm hoping someone else can confirm that XMP has this impact on Turbo, and that it's not just a side effect of some other setting I need to change.

Also, while Core Temp noted a rise in frequency, it did not show a change in multiplier. So I'm also not sure which results I should trust.

Build specs are in my sig. I'm running with BIO F4g, though I saw (I'm fairly certain) the locked multiplier - ie disabled Turbo - on F3 as well.

I'll link to 2 screenshots. Note the difference in the XMP OFF screenshot between CoreTemp and CPU-Z at Frequency, Multiplier, and Bus Speed. (If there's a better way to add images please let me know.)

First screen shot, XMP is turned ON, Prime95 is running 1 thread:
http://i867.photobucket.com/al...MaxMultiplierisx22.png

Second screen shot, XMP is turned OFF, Prime95 is running 1 thread, discrepancies between CPU-Z and CoreTemp:
http://i867.photobucket.com/al...MaxMultiplierisx22.png


Also, don't know if this is helpful but I took shots of the CPU-Z Memory tab as well.
With XMP turned ON: http://i867.photobucket.com/al...ime95on1CoreandXMP.png
With XMP turned OFF: http://i867.photobucket.com/al...rime95on1Coreand-1.png

 

[ekoostik]

I think I've found the answer to my problem. Would still like to get a second opinion or confirmation if anyone else out there knows about this. It probably occurs on all Gigabyte P55 boards.

I had read that the turbo mode would not be enabled on the Gigabyte boards if the power saving features were not turned on. I had previously checked (or so I thought) that these were turned on and because Turbo was working I assumed they were turned on. After more digging and reading and this being the only indication I could find I double checked the BIOS. Turns out these fields were not set to "Enabled" (even one the manual claims is Enabled by default). Instead they were set to "Auto". So, though I have not found proof of this anywhere, it is my belief that when set to "Auto" the mother board will allow the states if you have not done any OCing, including changing RAM to XMP.

I changed a number of the settings from Auto to Enabled. My board now idles with a multiplier of x9, (which if I did the math right is about 1.2GHz, I'm not at it right now so I can't check). And when I run a single thread of Prime95 it hits a multplier of x26 and the max speed of 3.46GHz. Turbo now appears to be working with RAM set to XMP.

Note: this is as reported by CPU-Z. CoreTemp never reports a multiplier and speed higher than x22 and speed of ~2.93GHz. I'm hoping CPU-Z is correct and CoreTemp does not read this processor correctly!

The changes I had to make in the BIOS were on the Advanced CPU Core Features page:
Intel Turbo Boost Tech. - changed from Auto to Enabled
CPU Cores Enabled - left as All
CPU Multi-Threading - left as Enabled
CPU Enhanced Halt (C1E) - changed from Auto to Enabled
C3/C6/C7 State Support - changed from Auto to Enabled
CPU Thermal Monitor - changed from Auto to Enabled
CPU EIST Function - changed from Auto to Enabled
Bi-Directional PROCHOT - changed from Auto to Enabled

It sure would be nice if Gigabyte explained under what conditions "Auto" would result in Enabled vs. Disabled. But since they don't (or I couldn't find it), I had to assume that if I changed any settings, all of the Autos would be treated as Disabled.

If anyone can shed any additional light, please do!

 

[ekoostik]

I have been doing some further testing. I reset the BIOS to optimized settings. Then I set Extreme Memory Profile (X.M.P.) to Profile1. From there I tested different System Memory Multiplier (SPD) settings. Turbo worked fine without any additional BIOS changes when I set the SPD to 8.0 and 10.0. However, when set to 12.0 or Auto, Turbo did not work without the additional changes BIOS configuration changes I previously mentioned.

I have a few other tests I want to run. Hopefully I'll get to them soon and will post back whatever I find.

 

[mc866]

I have the same mobo/proc combination as you, all of my parts are sitting at home right now. I'm going to get started on my build tonight, not sure how far I get this weekend but I'm very interested in your findings and will try and post some more info once I get my system up and running.

 

[mc866]

I haven't messed with any of my BIOS setting just yet. I just started it up and installed Win7 Ultimate. At idle CPU-z is showing the multiplier at X11 with the core speed at 1199.2. When I run Ripbot264 it pushes all 4 cores up to 100% utilization and cpu-z is showing the multiplier at x21 and the core speed at 2798.2. I haven't done much for single/dual thread testing but I know I did see the multiplier get up to 25 or 26. I'm running F3 bios, not sure if any of this info helps out.

 

[ekoostik]

That does help, thanks. I believe Turbo is being disabled because Gigabyte is considering my use of XMP as overclocking and so all the "Advanced CPU Core Features" that were set to Auto are being treated as Disabled. Therefore Turbo is also disabled.