You don't want to use Hyperthreading on 2000 - there are some issues on that OS. XP/2003 or above. As to the mem/IO switch - I have to believe that memory is the best setting. I don't know what the bios setting actually does, but presumably it is doing something like playing with device priorities at the bus level. tim _____ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Schneider, Chad M Sent: Wednesday, November 30, 2005 8:39 AM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: HP Proliant Server BIOS setting for CPU performanc e..... I guess I have not noticed enough of an issue with hyperthreading, to turn it off. _____ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of M Sent: Tuesday, November 29, 2005 3:25 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: HP Proliant Server BIOS setting for CPU performance..... Hello there, I found the settings on our BL20Ps last year when i was testing Hyperthreading on Windows 2000. I was checking the performance of a 16 bit application and then another server with our core apps on. I was most disappointed when i noticed zero difference when comparing with other identical servers (save the bios change). We had around 30 users for testing per box ----- Original Message ----- From: Jeff Pitsch <mailto:jepitsch@xxxxxxxxx> To: thin@xxxxxxxxxxxxx Sent: Tuesday, November 29, 2005 5:08 PM Subject: [THIN] Re: HP Proliant Server BIOS setting for CPU performance..... See that's what I was thinking. all the I/O from the sessions. Mouse and keyboard in particular. Jeff On 11/29/05, Matthew Shrewsbury <MShrewsbury@xxxxxxxxxxxxxxx> wrote: Hmmm I/O is always the slowest so set it for best I/O. Of course I know nothing on the subject but it is my best thought. Matthew Shrewsbury, MCSE+Internet MCSE 2000 CCA Server+ Senior Network Administrator -----Original Message----- From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pitsch Sent: Tuesday, November 29, 2005 11:02 AM To: thin@xxxxxxxxxxxxx Subject: [THIN ] HP Proliant Server BIOS setting for CPU performance..... Ok, I just came across this in the BIOS settings when I went to turn off hyperthreading. You can set the performance for the CPU to 'optimized for memory' or 'optimized for I/O'. It is defaulted to 'optimized for memory'. Anyone have any thoughts on this?