Comments on: Windows OS Power Saving Feature Directly Affects CPU Performance

By: bradmcgehee

bradmcgehee — Wed, 18 Aug 2010 20:36:38 +0000

Database Zealot–Thanks for the reference to the Microsoft paper. The link in your post doesn’t work, but I have fixed it and it works below.

http://download.microsoft.com/download/5/B/D/5BD5C253-4259-428B-A3E4-1F9C3D803074/WS08%20R2%20Power%20Savings%20White%20PaperTDM.docx.

If you want to know a little more about what I do from day to day, check out this post: http://www.bradmcgehee.com/2010/06/travel-tips-from-an-intrepid-traveling-dba/, as it describes a little about my travel. When I am not traveling, I work out of my home office, eight hours a day writing (for the most part).

Have no idea when I will be in Wellington next time. Depends on where Red Gate wants to send me. Next time I come, I hope to be able to spend more time.

By: The Database Zealot

The Database Zealot — Wed, 18 Aug 2010 20:18:50 +0000

So doing some digging this morning (For me in NZ anyway) I discovered this little gem:

download.microsoft.com/…/WS08%20R2%20Power%20Savings%20White%20PaperTDM.docx

A white paper from Microsoft discussing the advantages and disadvantages of power saving modes in Windows Server 2008 and Windows 7. Interestingly the modern day ACPI allows for power management control between the software and the CPUs as well as the usual suspects (hard disk, monitors etc). You might say, ‘Well, duh, where you been TDZ?’. Well… I’ve been busy here in sunny New Zealand and we are still using egg cartons for servers. Not really. Anyway I digress.

So there we have it.

Another interesting point (which you may have already mentioned Brad – apologies… but i’m in the zone here and can’t scroll up to check…), is default Windows Server 2008 power management is set to BALANCED. Watch out for this guys and girls… As this definitely affects CPU throughput. I for one will be checking our servers out ASAP.

On a different note, I’d love to see an article about: ‘Being Brad – a day in the life of…’…? Reckon it could happen?

TDZ

PS When you back in Wellington, Brad?

By: bradmcgehee

bradmcgehee — Wed, 18 Aug 2010 03:00:34 +0000

As far as I know, the Geekbench test is only for the CPU and the memory, not for any other devices in the server. In the future, I hope to do more testing on my DAS to see how its performance comes into play. I don’t have access to a SAN for testing, but I imagine that the results would be similar no matter what type of disk space is being used. Of course, the only way to know for sure is to test, as each hardware configuration is somewhat different.

By: The Database Zealot

The Database Zealot — Wed, 18 Aug 2010 02:31:57 +0000

Also, I forgot to say (Sorry, my coffee meter ran out and the dog has run off with my tea bags…):

‘Would you get the same results with SAN attached disk?’

TDZ

By: The Database Zealot

The Database Zealot — Wed, 18 Aug 2010 02:30:09 +0000

This is interesting. Was the cause directly the CPU being under powered? or rather the disk controllers/disks affected by the power save, which inturn acted as a bottleneck with Geekbench displaying the symptom?

Good post Brad.

TDZ

By: Brad M. McGehee (@bradmcgehee) posts Windows OS Power Saving Feature Directly Affects CPU Performance | SQL Aloha | sqlmashup

Tue, 27 Jul 2010 14:31:58 +0000

[...] Brad M. McGehee (@bradmcgehee) posts Windows OS Power Saving Feature Directly Affects CPU Performance | SQL Aloha Posted on July 27, 2010 by sqlmashup Windows OS Power Saving Feature Directly Affects CPU Performance [...]

By: Mark Broadbent

Mark Broadbent — Tue, 27 Jul 2010 06:59:30 +0000

Excellent article. The difference is staggering, thanks for highlighting this!

By: bradmcgehee

bradmcgehee — Tue, 27 Jul 2010 01:42:13 +0000

Dave, I also generally tweak the settings using Advanced Settings, but based on this test, I’ll be sure to perform benchmarks before and after each tweak just to see exactly how it affects the CPU.