Gearslutz.com - View Single Post - Could this be why the Nehalem Mac's aren't faster?

valis · 8th February 2010

Ok well thanks for the correction.

Since the EIST moniker is indeed speedstepping (Enhanced Intel SpeedStep® Technology) and since disabling EIST in the bios always disables speedstepping in my experience as well I had figured the two were connected always. I do have C1-4 and C1E exposed in the bios settings on my system, and disabling EIST disabled Speedstepping altogether (regardless of what C-states I allowed.) If that's not the case on Nehelem Xeons then I appreciate the correction (I'm on harpertowns still.)

At a few forums for webhosts / enterprise IT chat stuff they had reported that disabling speedstepping on nehelems required at least the passive copper coolers with a fan added (or better aftermarket coolers) to keep system temps in their preferred target range. I know that my older Harpertowns run considerably cooler and so disabling C1E/EIST in bios and setting the OS to run in high performance mode does increase my temps in the system (which are already warm due to the fb-dimms) so I have to run the fans at a higher profile to keep things under my preferred target temp for the system.

My Core2 era laptop is even worse when running full throttle via bios & windows settings, and I've heard that when people use Macbook Pros with the speedstep disabler (which is the only way of doing this on the Mac Pro that I know of offhand) they get extremely warm (although technically within tolerances still.) Given that the 45nm nehelem derivatives are known for running warmer than normal and that some people already report uncomfortably warm temps in their 2009 Mac Pro's I figured it might be a good thing to look out for. But if I'm mistaken in my understanding it's certainly good to know where...

8th February 2010	#19
valis Lives for gear Joined: Apr 2006 Location: Northwest USA Posts: 3,003	Ok well thanks for the correction. Since the EIST moniker is indeed speedstepping (Enhanced Intel SpeedStep® Technology) and since disabling EIST in the bios always disables speedstepping in my experience as well I had figured the two were connected always. I do have C1-4 and C1E exposed in the bios settings on my system, and disabling EIST disabled Speedstepping altogether (regardless of what C-states I allowed.) If that's not the case on Nehelem Xeons then I appreciate the correction (I'm on harpertowns still.) At a few forums for webhosts / enterprise IT chat stuff they had reported that disabling speedstepping on nehelems required at least the passive copper coolers with a fan added (or better aftermarket coolers) to keep system temps in their preferred target range. I know that my older Harpertowns run considerably cooler and so disabling C1E/EIST in bios and setting the OS to run in high performance mode does increase my temps in the system (which are already warm due to the fb-dimms) so I have to run the fans at a higher profile to keep things under my preferred target temp for the system. My Core2 era laptop is even worse when running full throttle via bios & windows settings, and I've heard that when people use Macbook Pros with the speedstep disabler (which is the only way of doing this on the Mac Pro that I know of offhand) they get extremely warm (although technically within tolerances still.) Given that the 45nm nehelem derivatives are known for running warmer than normal and that some people already report uncomfortably warm temps in their 2009 Mac Pro's I figured it might be a good thing to look out for. But if I'm mistaken in my understanding it's certainly good to know where...