danwat1234
New member
Optiplex 7040, 7050 and 5040 Small Form Factor PCs use a full-fat 65w i5-6500 or i5-6600 CPU and regular stock sized Intel cooler. Does the job very well. But there is efficiency to be gained as it is for most computers. Unfortunately, in newer BIOS versions vcore is locked. Cuz Plundervolt? So, use this BIOS;
7040: 1.5.9. https://www.dell.com/support/home/en-ca/drivers/DriversDetails?driverId=8XKRJ
7050: 1.8.2. https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=0n4gd
5040: 1.4.5. https://www.dell.com/support/home/en-us/drivers/DriversDetails?driverId=H56N1
Showing the process of flashing; https://youtu.be/MlrrrEDza2U
Version of Intel XTU to use for Skylake undervolting; 6.2.024 , why? Because.. Intel drops support for chipsets more than a few years old apparently. Could use Throttlestop instead and can setup to start on boot with Task Scheduler. it's a much smaller software. Download Intel Extreme Tuning Utility 6.2.0.24 for Windows 7, Windows 7 64 bit, Windows 8, Windows 8 64 bit, Windows 8.1, Windows 8.1 64 bit, Windows 10, Windows 10 64 bit Links down? Let me know.
Tip: After flashing the BIOS, YOU MUST reset to BIOS defaults because the vcore will still be locked until you do that. Also, do not then restore user settings or whatever it is called. That restores the vcore, again. I got stuck on that for hours. Manually change the settings back how you want. Now the sliders in XTU should be enabled.
-0.12V is the sweet spot for midrange Skylakes. Just works full load or idle. 0.07V is safe for midrange Haswell (4th gen), they are more sensitive.
Powershell script for older XTU so settings apply on reboots https://www.youtube.com/watch?v=_dol1epwxeA
Or, set up Throttlestop.
Efficiency #s i7-8700 with thirsty 3.5"
Pwr-limit Power consumption is 100% load running Distributed Computing. Would be higher with Prime95.
40w is about 3.15GHZ, XTU 2.0 score 1768 68 watts
50w is about 3.45GHZ. score 2041 82 watts -sweet spot.
65w is about 3.75GHZ, score 2245 103 watts.
so 10% more performance but 25.6% more power. 14.4% more efficient.
No undervolt, greyed out.
set to infinity is ~4.25GHZ score 2439 150 watts
--
Dell i5-6500 with ssd, 56 watts.
0.06v offset, 51 watts.
0.075v another watt less.
0.09v 49 watts
0.11v?? .12v???47w .135v?46w .15v?45w .17v crashes when it goes idle.
setting to .12v very stable there. Box only takes 80% the power, same clocks!
7040: 1.5.9. https://www.dell.com/support/home/en-ca/drivers/DriversDetails?driverId=8XKRJ
7050: 1.8.2. https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=0n4gd
5040: 1.4.5. https://www.dell.com/support/home/en-us/drivers/DriversDetails?driverId=H56N1
Showing the process of flashing; https://youtu.be/MlrrrEDza2U
Version of Intel XTU to use for Skylake undervolting; 6.2.024 , why? Because.. Intel drops support for chipsets more than a few years old apparently. Could use Throttlestop instead and can setup to start on boot with Task Scheduler. it's a much smaller software. Download Intel Extreme Tuning Utility 6.2.0.24 for Windows 7, Windows 7 64 bit, Windows 8, Windows 8 64 bit, Windows 8.1, Windows 8.1 64 bit, Windows 10, Windows 10 64 bit Links down? Let me know.
Tip: After flashing the BIOS, YOU MUST reset to BIOS defaults because the vcore will still be locked until you do that. Also, do not then restore user settings or whatever it is called. That restores the vcore, again. I got stuck on that for hours. Manually change the settings back how you want. Now the sliders in XTU should be enabled.
-0.12V is the sweet spot for midrange Skylakes. Just works full load or idle. 0.07V is safe for midrange Haswell (4th gen), they are more sensitive.
Powershell script for older XTU so settings apply on reboots https://www.youtube.com/watch?v=_dol1epwxeA
Or, set up Throttlestop.
Efficiency #s i7-8700 with thirsty 3.5"
Pwr-limit Power consumption is 100% load running Distributed Computing. Would be higher with Prime95.
40w is about 3.15GHZ, XTU 2.0 score 1768 68 watts
50w is about 3.45GHZ. score 2041 82 watts -sweet spot.
65w is about 3.75GHZ, score 2245 103 watts.
so 10% more performance but 25.6% more power. 14.4% more efficient.
No undervolt, greyed out.
set to infinity is ~4.25GHZ score 2439 150 watts
--
Dell i5-6500 with ssd, 56 watts.
0.06v offset, 51 watts.
0.075v another watt less.
0.09v 49 watts
0.11v?? .12v???47w .135v?46w .15v?45w .17v crashes when it goes idle.
setting to .12v very stable there. Box only takes 80% the power, same clocks!
