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peterlm
1 Copper

Strange BIOS setting in new XPS 8000 (i7 870 CPU)

Yesterday I got my XPS 8000 with an i7 870 CPU.

I was surprised to see that in the BIOS, both speedstep and sleepstates (C1, C3 etc) had been DISABLED.

According to what I have learned, this prevents "turbo boost" to work and also wastes power while the computer is idle:

For turbo boost to work (i.e. if 2 or 3 cores are doing nothing, the other core(s) are stepped up to a higher clock speed) the sleep states must be enabled, i.e. the idle cores must be allowed to go into a sleep state mode. Also speedstep scales down the clock when a core is idle, thus saving power/heat and allowing the remaining core(s) to run faster.

Is there any good reason that an XPS 8000 is delivered with these BIOS settings?

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9 Replies
peterlm
1 Copper

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

I tried to change the mentioned BIOS settings and used a test program to observe the clock speed of each of the CPU cores.

As expected, with the default BIOS settings, turbo boost never came into use. This means that a single threaded program is limited to 2.93Ghz.

By enabling both settings, turbo boost was turned on and a single threaded program runs at higher speed (up to about 3.5Ghz).

I am really puzzled why Dell delivered the XPS 8000 with these settings disabled. I have to assume that this is an error. Can anyone shed any light on this?

 

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yustas33
1 Copper

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

This is very interesting. I am getting ready to order XPS 9000 and would like to know what the deal is with this as well.

By the way, since you got the i7 CPU, why did you order XPS 8000 and not XPS 9000?

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Spaz888
2 Bronze

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

Oh gosh...dont tell me this.  I wonder what else they did that they shouldnt have.

I would speak to the tech support supervisor and find out what's going on.

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peterlm
1 Copper

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

In case someone is interested: I had contact with dell support, and there is no reason why the settings were disabled. In fact it must be considered an error to ship a system with speedstep and sleepstates disabled, i.e. to disable turbo boost.

 

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Dezert68
1 Copper

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

I just ordered the XPS 800 with i7 processor. How would one go about enabling the speedstep and sleepstates if they are disabled?

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McKay95
1 Copper

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

"I just ordered the XPS 800 with i7 processor. How would one go about enabling the speedstep and sleepstates if they are disabled?"

You can hit F2 i believe at bootup to enter the bios menu and enable them there.

Interestingly enough i also noticed my speedstep was disabled. I recently reset my cmos jumper to troubleshoot another issue in doing so that restores the default bios settings. I was able to verify that speedstep and c-state are disabled by default even though there system setup manual says otherwise in the following link.

http://support.dell.com/support/edocs/systems/studio8000/en/SM/sys_setu.htm#wp1005451

 

  • Hyper-Threading — Enabled or Disabled (Enabled by default)
  • Intel SpeedStep™ Tech — Enabled or Disabled (Enabled by default)
  • Intel® C-STATE Tech — Enabled or Disabled (Enabled by default)
  • Intel® Virtualization Tech — Enabled or Disabled (Enabled by default)
  • Limit CPUID Value — Enabled or Disabled (Disabled by default)
  • Execute Disable Bit — Enabled or Disabled (Enabled by default)
  • Multiple CPU Core — All or 1 or 2 (All by default)

 

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z06psi
2 Iron

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

Good information to know. TTT

XPS8000, Intel DP55BS MB, i7 860@3.6Ghz w Zallman 9700 cooler, 1TBx2 RAID, Intel X25MG2 SSD, ASUS EAH HD5870, 8GB 1600 Corsair XMS Dominator, 3008WFP, Ultra Gold 550 Win7 x64

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alero90
2 Iron

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

subscribe.

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Siobhra
2 Iron

Re: Strange BIOS setting in new XPS 8000 (i7 870 CPU)

Apparently, the speedstep and sleep state settings are not even available in the A13 BIOS setup for the XPS9000.  The only settings displayed are for the XD bit, and to enable or disable the cores.  How would one even determine the status of the sleep and speedstep modes with this BIOS, let alone change them?  I have a Core i7 975 Extreme Processor at 3.33Ghz

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