Is my Rampage V Extreme Killing DIMMs?

[metallurch0]

Hi Everyone,

I have a strange problem with a rig I built a few months ago, I've got a Rampage V Extreme with a 6950X and 64GB of 3000MHz Corsair Vengeance LED memory in an 8x8 configuration. The power supply is a Corsair AX1200i and the motherboard and CPU are cooled by a custom loop watercooler with an EK full board block, 480mm radiator and EK D5 pump.

When I first built the system in October last year everything worked perfectly, fired it up and updated the motherboard to the latest firmware (3301 at the time). Not being an overclocking expert I just loaded the built in 10-core overclocking profile that came with the board, manully set the memory to its native 3000MHz frequency and started using it. Ran a few stress tests and benchmarks with no issues, CPU temperature never seems to go above 62 Celsius under full load and at idle it's practically room temperature.

Since I built it I've completed several demanding games, stuff like Mafia 3, Tomb Raider, Dishonored 2, etc... all in 4k with all settings on ultra and with 4 - 6 virtual machines running on VMware workstation in the background and the whole time the system has been rock solid, it hasn't crashed once since I built it.

So a couple of months ago I fired it up and noticed I only had 48GB of RAM, memory channel D seemed to be totally dead. I went through all the usual troubleshooting steps (swapping DIMMs round, resetting the EFI, trying the DIMMs in other systems) and still faced the same problem. So I removed the board from the system with the CPU and memory in place and took it back to the shop where I bought it. They have a test bench and plenty of hardware and after an hour or so they determined that one of my memory modules had died. Still being under warranty they swapped the whole kit and I went home with 4 new DIMMs.

Once I'd rebuilt it I had my full 64GB back, but I couldn't run the memory at 3000MHz. Every time I tried to turn it up the system wouldn't even POST. So this time I left everything at stock settings with the memory running at 2133MHz and no overclock. A couple of days ago I fired it up and found once again I only have 48GB of RAM!

It would appear my system has killed another DIMM, this time in channel B. Over to you guys, I'm extremely confused. The strangest thing is that even in this state the system is still 100% stable, even my VMs haven't crashed once. So at some point I've lost a memory channel and not even noticed.

Any help would be greatly appreciated, I'm totally lost.

Cheers.

[JustinThyme]

Is that memory kit on the approved vendors list?

[metallurch0]

JustinThyme wrote:
Is that memory kit on the approved vendors list?

Not that kit specifically, Corsair Vengeance is on the list but I was under the impression that the Vengeance LED is the same thing with some fancy lighting effects. I noticed all the memory on the official compatibility list is 2133MHz too, so I'm guessing there's loads of people out there running kits which technically aren't supported?

[JustinThyme]

metallurch0 wrote:
Not that kit specifically, Corsair Vengeance is on the list but I was under the impression that the Vengeance LED is the same thing with some fancy lighting effects. I noticed all the memory on the official compatibility list is 2133MHz too, so I'm guessing there's loads of people out there running kits which technically aren't supported?

There are tons that work and are not on the approved vendors list. Some work well, some dont work at all and some get cooked.

Seeing how ASUS went through the trouble to test and verify the kits on the approved vendors list and they give plenty of options I try and stick to the list. It also helps in the times of needed support as you wont hear any blame put on a kit if its on the list.

[metallurch0]

JustinThyme wrote:
There are tons that work and are not on the approved vendors list. Some work well, some dont work at all and some get cooked.

Seeing how ASUS went through the trouble to test and verify the kits on the approved vendors list and they give plenty of options I try and stick to the list. It also helps in the times of needed support as you wont hear any blame put on a kit if its on the list.

Yeah fair point, I guess I took a gamble. I'm hoping it's not a compatibility issue as I don't fancy having to fork out for another memory kit. I just took another look at the list and noticed I was only looking at the first page! I never even noticed all the other kits on there.

[Chino]

Try loosening the screws for your waterblock a little.

[metallurch0]

Chino wrote:
Try loosening the screws for your waterblock a little.

Ok cheers, I'll see if I can find some time to do that this weekend. I'll post the results, if that makes my DIMM come back I'll be delighted but I suspect I might have to make another trip to the shop.

Thanks.

[Arne_Saknussemm]

You say 64GB kit 8x8 and then say the place you bought it from swapped out 4 dimms

That would mean you are running 2 different kits of memory. Which is not a good start. https://rog.asus.com/forum/showthread.php?57038-Don%92t-combine-memory-kits!-The-meat-and-potatoes-o...

Missing RAM can indeed be from displaced CPU so checking the block is mounted well and evenly would be a first step...though this would normally show up after installation not usually a while after installation...

Can also be from dying memory controller on the CPU.. but less common. Or from a dying motherboard. But let's not get too pessimistic...

Might be just another stick dead from the original or replacement kit. Vengeance is not the best in my opinion for high end builds.

You could also try to raise voltage a bit and see if sticks reappear...

[metallurch0]

Arne Saknussemm wrote:
You say 64GB kit 8x8 and then say the place you bought it from swapped out 4 dimms

That would mean you are running 2 different kits of memory. Which is not a good start. https://rog.asus.com/forum/showthread.php?57038-Don%92t-combine-memory-kits!-The-meat-and-potatoes-o...

Missing RAM can indeed be from displaced CPU so checking the block is mounted well and evenly would be a first step...though this would normally show up after installation not usually a while after installation...

Can also be from dying memory controller on the CPU.. but less common. Or from a dying motherboard. But let's not get too pessimistic...

Might be just another stick dead from the original or replacement kit. Vengeance is not the best in my opinion for high end builds.

You could also try to raise voltage a bit and see if sticks reappear...

That is a very interesting article, I always thought if the rated timings were the same then it was a guaranteed you could achieve those latency figures across the board. Never realized the modules were set up to only work with a certain density. I'm guessing the tolerances are getting finer as everything gets quicker too. I've certainly never encountered an issue like this before.

Now I've read this I'm actually considering trying to get it swapped, especially if it happens again. First I'll try what you guys suggested, if I find the time I'll re-seat everything this weekend, loosen the cooling block and play with the voltages. The strangest thing to me is how the system remains so stable, I would have put money on a system with an issue severe enough to kill DIMMs or loose a memory channel being virtually unusable.

[metallurch0]

Quick update guys, at weekend I tried loosening the waterblock a bit and tried playing with the memory and system agent voltages. Unfortunately it made no difference, I still only had 3 memory channels showing up.

The good news is having taken my memory back to the store there is a chance they might be able to swap out the two 4x8 kits for an 8x8 kit of Corsair Dominator which is also on the approved memory list for my board. After reading that article about mixing memory kits I'm really hoping they do, I get the feeling this might be what's causing this issue. Currently waiting on an e-mail from the store with their decision, fingers crossed. I'll let you know the outcome.

Cheers