e2160 + p35 DS3L stock stability "CPU Multi-threading" BIOS opt


May 19, 2008
Hi. my first post here. Its a credit too all the great information found here that i haven't had to post a question till now. A big Thank you goes out to the forums for the help I've gotten w/o ever having to ask a thing.

I bought a new p35 DS3l +e2160 to build my brother a new PC. Money is tight so its a slow build cannibalizing a stick of my RAM and a backup PSU + 7600GT. To play with and test the new parts i just swapped them out for my PC's mobo+CPU. Hmm you might need/want some system specs.

My PC: New PC:
Mobo: P965 DS3 Mobo:none
CPU:e4300 CPU:none
PSU:Antec 650 trio PSU:Rosewill 550 -> my back up parts.
Graphics:7900GT Graphics:7600GT
RAM:G.skill DDR 800 2x1gb RAM:none

So, i swapped the new p35 ds3l + e2160 for my stable 965 ds3 + e4300 and split the ram between the 2 systems. Allowing me to test the new components with proven stable ones.

On the new p35 DS3l F7bios+e2160 i can't seem to nail down my stability problems @stock speeds. After multiple reformat/ reinstalls and hours of research, i noticed a BIOS setting in an OC guide that didn't match mine. "CPU Hyper-Threading" was disabled in the guide, mine is set to enable. e2160's do not support Hyper threading according to the spec sheet. The proverbial light bulb went off over my head.

I turned off the CPU hyper-threading option in bios and rebooted. After reboot i only had 1 core running in CPU-Z, task manager, and process explorer. Everything showed two working cores before. Since the e2160 doesn't have support for HT and when its turned off i only get 1 core working I'm left to assume that maybe my HAL is screwed up and a reinstall with "CPU hyper-threading" option turned off in BIOS will possibly correct my stability issues. Either that or I'll have a 1 core CPU still.

The 965 PC is still running flawlessly with a lesser PSU, Vid card and half the ram. p35+e2160 has performance deterioration under constant load. The pc will not crash it gets extremely sluggish and choppy. While exhibiting the sluggishness the cpu load will drop. To simulate near 100% load i logged into WoW while running spybot and PE to watch what was going on. At about 75% of spybots scan the CPU usage starts spiking downward, going from a steady ~80% usage to an erratic 10-20% usage. At this point the PC gets sluggish, needless to say gaming isn't a pleasant experience.

Troubleshooting this has been a huge PITA. It will run prime95/orthos for hours, overnight wont crash it even. But after as little as an hour it starts showing the CPU downward spikes but nothing will actually crash it which is driving me bonkers! Ram passes memtest+ temps are within range according to speedfan (calibrated via computronix temp guide) load at stock using TAT for load = ~49* Core0/1 @ 24* ambient.

I guess i should get to the question of this post b-4 it becomes a novel. How should the "CPU Hyper-threading" option be set in BIOS for an e2160 on a p35 DS3L? If its disabled then my problem could be found. I really need to hammer this out before my return window closes on the mobo.

Thanks for your time and any help you may have. I've been on this like an addict on crack over the weekend, my mind is burnt up right now.

Edit: the actual option in BIOS is "CPU Multi-threading", in the manual and screen shots i was looking at it read hyper threading. e2160 should "Multi-thread" just fine. *sigh*

Holy cow i aint reading all that!

Reset the cmos on the system and use the default settings to first see wether the system is stable and go from there - dont mess around or overclock till your components are aok and working, if its not check the psu and ram etc.

post back with a simple and short question.


Oct 1, 2004
Check these bios settings... (taken from overclockers.net post)

CPU Enhanced Halt (C1E): Enables or disables Intel's power-saving function; when enabled, the CPU core frequency and voltage are throttled down to conserve power during system halt state.

CPU Thermal Monitor (TM2): Enables or disables Intel's overheat protection function; when enabled, the CPU core frequency and voltage are throttled down when the CPU overheats.

CPU EIST Function (SpeedStep): Enables or disables Intel's power-saving function; when enabled, the CPU core frequency and voltage are throttled down to conserve power dynamically during usage.

good luck!

Edit: Can't remember (I just did this too :) ) is F7 the latest bios? If not, then you should update.


May 19, 2008
Sorry for the rambling post, i needed sleep badly, 40 hour marathon over the weekend on this pc.

All power saving options are off, all extras like USB, IDE, Lan, parallel/serial ports, and on-board sound are off for troubleshooting.

F7 is the latest non-beta BIOS. Really didn't think i should need the beta's. F8a/b/f all look like 45nm CPU updates. BIOS updates are my bane. I actually had a power outage while doing the last BIOS update I did. Yeah i admit it, I'm a bit scared of BIOS updates now.

When the problem starts under a lode the CPU usage graph changes from a smooth line to a roller coaster of ups(80%) and downs(1-3%). The downward spikes correlate with I/O bandwidth upwards spikes.

Do you think the boot.ini /usepmtimer switch could make a difference?