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02-19-2020 05:30 PM
I’ve upgraded from a e5-1660 v2 to a e5-1680 v2. After new cpu install it is only showing 6 cores and giving 921 front usb error on boot. Bios is up to date. Any thoughts?
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02-19-2020 08:11 PM - edited 02-19-2020 08:28 PM
What is your Z420's boot block date, from BIOS? That is, is it a version 1 or a version 2 Z420?
Did you get your processor from a reputable seller? There have been some scams in the past for these previously very expensive processors.... There are "Q" versions that are pre-release "qualification" versions of the processors that can have their stainless laser-etched lids switched, and those generally don't work as well as the true post-release versions.
02-20-2020 03:04 AM
it’s a version 2 boot block. As for being reputable, it’s hard to say. This was purchased off eBay. Using intel diagnostic software it passes all test still showing 6 cores using 85w. I’ve swapped the 1660 back in, which is operating normally though the error 921 remains.
02-20-2020 05:14 AM
I’ll double check when I shut it down this afternoon. I didn’t unplug the front usb header but maybe I bumped it while rearranging cables. I’ve been in contact with the seller, they’ve had me run every test, intel or otherwise. No luck. Adamant it tested fine when shipped, which to be fair it’s still testing fine only showing 6 cores. Bios is set properly, up to date, and msconfig is only giving option for 12 logical cores.
02-20-2020 07:00 AM
I'd now do the long version of resetting CMOS. Unplug from any power, disconnect all peripherals including mouse/keyboard, remover motherboard battery, push and hold power on-button for 30 seconds, push and hold CMOS reset motherboard button 30 seconds, wait 1 hour, repeat x 1. You want to drain off any capacitor charge everywhere. This will ensure it is set back to factory defaults. Some settings can get "stuck" in CMOS and this approach can unstick them. I had something like this happen with a X5690 being placed into a Z400 way back, and only 4 of the 6 cores were being seen. This got me properly to 6 cores on that build.