memtest86+ showing different speeds for memory slots

I have a Pegatron Violet6 motherboard. There are four memory slots, and I have four 4-GB sticks of RAM.
I've been having a lot of BSODs lately, so I decided to test my RAM again.

Putting in one stick at a time and running memtest86+ gives:
Slot 1: All four sticks test okay and show 666 MHz (1333 MHz and 9-9-9-24)
Slot 2: All four sticks test okay and show 666 MHz
Slot 3: All four sticks test okay and show 400 MHz
Slot 4: All four sticks test okay and show 200 MHz (7-7-7-20)

If I put RAM in slots 1 and 2 and run memtest, it shows 666 MHz. But if I put something in slots 1, 2, and 3, I get 533 MHz.

Is my MB failing, or is this normal behavior? I'm currently only running with RAM in slots 1 and 2...is this going to work for a while, or should I be ordering a new motherboard?

Thanks!

I have never experienced readings like that, and can only guess as to what would cause it.

I tried looking for a motherboard manual with no luck. I thought there might be something in the RAM section about the slots that might explain it.

Installing RAM in odd combinations will toggle between dual channel and single channel mode but that should not change the speed. So it does not sound like anything normal.

You could be having trouble with voltage going to the slots. But even then I can't think of why that would knock the speed down.

Try running CPU-Z and see what it gives for RAM stats in different combinations.
You could populate all the slots and test it first.

There is something very odd going on, it seems.
Same stick of RAM for the memtest screenshots and the single-stick reports from Speccy/CPU-Z.

In slots 1-3, memtest86+ reports 666 MHz, 9-9-9-24
In slot 4 (same RAM stick), 200 MHz, 9-9-9-24

If I have RAM in 1 or 2 slots (any 1 or 2 slots) I get 666 MHz, 9-9-9-24 from CPU-Z.
But if I have 3 or more (anywhere) it shows 533 MHz, 7-7-7-20.

Weird, huh?

Not conclusive, but no BSOD in the day and a half or so I was running with RAM only in slots 1 and 2.

Thanks for the help.

Nice screen shots.

I do not see anything wrong with the RAM. You have a matched set of 4 modules and they all match in timings and every other spec. If I were going to bet, I would bet that the RAM is OK.

That is not a good thing. RAM is easy to replace, motherboards not so much.
And if I were going to guess that would be my guess - there is something going on on the motherboard.

Have you ever changed the Advanced Settings in BIOS, particularly in RAM? Overclocking anything?
Are you running in XMS mode? (It does not look like the Kingston RAM is XMS)
Have you tried resetting BIOS defaults?
Have you tried a ClearCMOS procedure?

Another thing - a long shot - is that if this is an AMD system you could look to see if you can run the RAM in constant "Unganged" mode. Just to see if that makes any difference.

Something with the MB was also my fear since all the RAM sticks produced the same readings.

No overclocking.

I'm not sure what you mean about running in XMS mode. The BIOS recognizes all 16 GB of RAM (startup screen reports all four slots being populated by 4 GB each), memtest sees all 16 GB when they're all in, the "System" tab in Control Panel lists 16.0 GB as the amount of installed RAM, and the Windows memory test program sees all 16 GB.


The only thing I've changed in BIOS was changing the video from onboard to the card when I installed it. I can reset BIOS if you think it's worth testing.

I've never done a ClearCMOS.

This is a weird system, IMHO, because it is an HP computer with an nVidia nForce 720a chipset but an AMD Athlon II X4 processor.
CPU-Z shows "Unganged" as the DC Mode whenever there is more than one RAM stick installed.

QPhysics said:

I'm not sure what you mean about running in XMS mode.

XMS is a RAM specification. XMS RAM can signal the motherboard as to what speed it can be run at. If the motherboard has the RAM "automatic overclock" setting set to XMS mode then the board will automatically make the adjustments needed to run the RAM at it's rated speed.
Since you do not know of XMS Mode we can assume that you system either does not have that feature or you are running in default mode - which is fine.

QPhysics said:

The only thing I've changed in BIOS was changing the video from onboard to the card when I installed it. I can reset BIOS if you think it's worth testing.

Resetting the BIOS to defaults would only be helpful if you had made a number of BIOS changes or were overclocking in any way. This probably will not change anything. But it is a can't hurt - might help sort of deal.
Just be sure to note all your current RAM settings so you can set them back to the way they were if the procedure yields no results.

QPhysics said:

I've never done a ClearCMOS.

ClearCMOS is going to do the same as resetting defaults, but with the added benefit of forcing the system to re-initialize and "enumerate" the system hardware fresh. This can correct some quirky problems. If interested in trying it let me know and I can post some instructions (if you can't find this in your PC manual)

QPhysics said:

This is a weird system, IMHO, because it is an HP computer with an nVidia nForce 720a chipset but an AMD Athlon II X4 processor.

AMD socket motherboards usually use an nVidia chipset, this is normal.

QPhysics said:

CPU-Z shows "Unganged" as the DC Mode whenever there is more than one RAM stick installed.

That is the default. But on motherboards with advanced system settings you can change the default setting to one that will run the RAM ganged even when there are 2 modules installed. I do not see any benefit in running a system like that. But in your case I thought it might be interesting to see if that changed anything in your odd readings.

I'm pretty certain I know where the jumper is to reset the CMOS.
As I can't think of anything bad that could come from clearing it, and if it forces the system to rescan the hardware (so maybe actually recognize the RAM upgrade in a way that it didn't a couple years ago when I went from 6 to 16 GB?)...I don't see any reason not to do it.