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BIOS 4804 - Very High DPC Latency

ChaosMinionX
Level 7
Hi there,

I have an Asus Rampage IV Forumla on BIOS 4804

I have been overclocking for a very long time, so I know its nothing with the overclock and I am leaning that its more to the BIOS having issues with DPC latency, but I am not entirely sure, I also have a NIC to look at that might be the cause.

Anyways heres the run down on the system

Intel 3930k @ 4.5GHz 45x100 (Patched in latest OROM, ASMEDIA drivers from Fernando's UBU)
32GB Corsair VengeancePRO DDR3 1866 9-9-9-27-CR1
2 HD7870 Crossfire 1200/1300
Killer 2100 NIC (latest driver 6.1.0.603)
Whole system is liquid cooled by a custom loop in a Corsair 800D

I have also tried running HPET on, and HPET off for system timers.
No BSODs either, or any sort of erratic behavior.

Latest Chipset driver, IRST driver, and everything else, PC passes Memtest86+, OCCT (Small/Med/Large 12hrs each), 20 passes of LinX running latest linpack binaries, and Prime95 (good old fashioned priority 9, using a custom setting)

I am running LatencyMon v6.00 and seem to be getting very high DPC from the Killer 2100 all of a sudden, prior to that it had not been acting this way, the OS is Windows 8.1 x64 (not running Update 1 for April), I am going to try reverting to an older BIOS and see if the same issue arises, or if its something with one of the drivers I have, but I just wanted to see if anyone else had issues like this with 4804, previously I was only seeing 132ms latency on these, and now its wayyy up there.

I also haven't ruled out the fact it might just be latencymon reading something wrong, recently it was updated to 6.00.

4,523 Views
4 REPLIES 4

ExcessiveGBH
Level 8
Turning off HEPT in BIOS is only part of it, you need to turn it off in OS as well by using this in CMD "bcdedit /set useplatformclock false" then reboot. To turn it back on "bcdedit /set useplatformclock true". Here is some links for more in-depth information. http://www.neowin.net/forum/topic/1075781-tweak-enable-hpet-in-bios-and-os-for-better-performance-an...
http://rog.asus.com/forum/showthread.php?23113-HPET-High-Precision-Event-Timer/page2&highlight=High+...
I have HEPT tuned off and my DPC went from 125us-65us to 12us flat lining it, this is with BIOS 4804.
System specs
Win 11 Pro 21H2
Rampage VI Extreme
BIOS 3801
I9 10920 @5.0GHz all cores
EK-KIT G360 (CPU only)
Samsung 960 PRO M.2 NVMe 1TB
Samsung 970 EVO M.2 PLUS NVMe 2TB
Kingston Fury Renegade 4TB PCIe 4.0 NVMe M.2 SSD with Heatsink
1 Samsung SSD 4TB EVO
1 X Samsung SSD 860 EVO 4TB
2 x 10TB drives
1 x 2TB drive
ASUS ROG Strix GeForce RTX 4090 OC 24GB @3015 MHz
32GB G Skill Trident Z 3466MHz 15-17-17-37
Corsair AX1200W PSU
Sound Denon AVC-A1
LGC1 77

ExcessiveGBH wrote:
Turning off HEPT in BIOS is only part of it, you need to turn it off in OS as well by using this in CMD "bcdedit /set useplatformclock false" then reboot. To turn it back on "bcdedit /set useplatformclock true". Here is some links for more in-depth information. http://www.neowin.net/forum/topic/1075781-tweak-enable-hpet-in-bios-and-os-for-better-performance-an...
http://rog.asus.com/forum/showthread.php?23113-HPET-High-Precision-Event-Timer/page2&highlight=High+...
I have HEPT tuned off and my DPC went from 125us-65us to 12us flat lining it, this is with BIOS 4804.


Can you post a test of LatencyMon of your PC here? I just want to compare and see if I have something more going on, I disabled HPET and turned off the platform clock in Windows and am still seeing the same behavior, spikes of 1000ms response on some items.

I dont have audio dropouts or anything, so could be a non issue.

ExcessiveGBH
Level 8
back soon
System specs
Win 11 Pro 21H2
Rampage VI Extreme
BIOS 3801
I9 10920 @5.0GHz all cores
EK-KIT G360 (CPU only)
Samsung 960 PRO M.2 NVMe 1TB
Samsung 970 EVO M.2 PLUS NVMe 2TB
Kingston Fury Renegade 4TB PCIe 4.0 NVMe M.2 SSD with Heatsink
1 Samsung SSD 4TB EVO
1 X Samsung SSD 860 EVO 4TB
2 x 10TB drives
1 x 2TB drive
ASUS ROG Strix GeForce RTX 4090 OC 24GB @3015 MHz
32GB G Skill Trident Z 3466MHz 15-17-17-37
Corsair AX1200W PSU
Sound Denon AVC-A1
LGC1 77

ExcessiveGBH
Level 8
Hope you sort it out. As you have Win 8 have you also tried this CMD? "bcdedit /set disabledynamictick on". Try with HEPT on and off.

34851
34850
System specs
Win 11 Pro 21H2
Rampage VI Extreme
BIOS 3801
I9 10920 @5.0GHz all cores
EK-KIT G360 (CPU only)
Samsung 960 PRO M.2 NVMe 1TB
Samsung 970 EVO M.2 PLUS NVMe 2TB
Kingston Fury Renegade 4TB PCIe 4.0 NVMe M.2 SSD with Heatsink
1 Samsung SSD 4TB EVO
1 X Samsung SSD 860 EVO 4TB
2 x 10TB drives
1 x 2TB drive
ASUS ROG Strix GeForce RTX 4090 OC 24GB @3015 MHz
32GB G Skill Trident Z 3466MHz 15-17-17-37
Corsair AX1200W PSU
Sound Denon AVC-A1
LGC1 77