Ram Addressing in Memtest86 V8.4

[lavere]

I'm sure this question has been answered before but my search button searches the entire site and I get many, many hits, so here it is:

Once I boot to the flash drive and the program opens, I'm presented with a default set of values for the ram I'm testing. If I accept these values and press 'start', the program freezes immediately. The suggested upper limit in my case is 0x22F000000 which seems to be larger than my ram. I found that if I enter an upper limit to test (such as 4096 as suggested on screen) the program will run. But is this testing the entire range of addresses on the ram module? I've tried specifying what I believed would be a reasonable upper limit for an 8GB stick of ram, but I must admit that I don't really know what I'm doing.
What is the proper procedure to test the entire stick, in my case 8GB?

[David (PassMark)]

No special setting should be required. It should automatically test the available RAM (the portion that isn't already in use by the UEFI BIOS itself, video card, or other hardware). Typically this available RAM is 90% to 99% of all the installed RAM.

The suggested upper limit in my case is 0x22F000000 which seems to be larger than my ram

This can happen if there is some other device in the memory map using some of the addresses. It isn't a fault.

If you see a lockup, then it could be a hardware failure, or it could be one of several known bugs in various UEFI BIOSs from various motherboard vendors.

Post the log from MemTest86 if you like.
https://www.memtest86.com/tech_debug-logs.html

[lavere]

Here is a fresh log file. I accepted all of the defaults and started the program. The timer froze at 2 seconds. What do you think? MemTest86.log

[keith]

Just to help people find this with search engines: This is a problem with MemTest86 and a Dell OptiPlex 390 with i5-2400 CPU, BIOS version A14 Release Date: 06/24/2018


Can you try setting the upper limit to 0x100000000 (32-bit addresses only). Then after that, try setting the lower limit to 0x100000000 (64-bit addresses only).

We suspect that there may be a bug in the UEFI BIOS when accessing 64-bit addresses. If this is the case, the former should work but the latter should fail immediately.

[lavere]

OK. I set the upper limit to 0x100000000 and ran the test. It completed the whole thing. I then reset the address range to default and set the lower limit to 0x100000000. When I (s)tarted the test the program froze at 1 second elapsed time. I'm including the zipped log of that session.
MemTest86.zip

[keith]

This appears to confirm the UEFI BIOS bug when accessing 64-bit addresses. Fixing this would require an updated BIOS from Dell or otherwise, the only workaround would be to just test up to 4GB of memory as you did by setting the upper limit address to 0x100000000.