Dell R720 NVMe Sadness

[coolrunnings82]

I picked up a Dell R720 recently and have been pretty stoked about its performance with dual 2670's. I upgraded to the NVMe hot-swap option that consists of a 4-port card that splits the PCI-E x16 slot 4x ways and connects to a hotswap bay in the front for 4x NVMe drives. Pretty freaking cool! Except when I benched my new P3700 it maxes out completely at 1719mb/s read and write. Not that that's slow or anything but I expected more. Come to find out that 4x breakout card seems to be limited to PCI-E Gen2. I would LOVE to be proved wrong but this sucks and I can't find any options in the BIOS to force things to negotiate at PCI-E Gen3 speeds. The Dell card part number is 0YPNRC.

Does anyone else here have a Dell R720 with the NVMe hotswap bay option that could verify that this card is indeed limited to PCI-E Gen2?

 

[MiniKnight]

That is a bummer!

 

[Patrick]

@coolrunnings82 I think they were made for the PCIe 2.0 p320h's so I guess it makes sense.

 

[coolrunnings82]

Yep, @Patrick, that is exactly it. I wish there was an upgrade card I could use though! Anyone know if the R730XD has this same limitation?

 

[Patrick]

Yep, @Patrick, that is exactly it. I wish there was an upgrade card I could use though! Anyone know if the R730XD has this same limitation?

If you get desperate and want to get the Micron SLC drives I think I have 2-4 of the 350GB Dell caddies and a at least four of the drives. They are in use but with some ridiculously low usage (<5GB writes/ day). I could probably swap them out for other drives.

 

[DERJ]

Yep, @Patrick, that is exactly it. I wish there was an upgrade card I could use though! Anyone know if the R730XD has this same limitation?

The R720 only supported 2.5" PCIe SSDs at Gen2 x4 speeds (that was all that were available at the time the R720 first launched.)

But to answer your question - no, the R730XD does not have the same limitation. It can connect 4 of the 2.5" PCIe SSDs at Gen3 x4 speeds.

And unfortunately, the R720 can not be upgraded - the card/cables used for connecting the front slots in the R730XD use a different style connector (mini-SAS HD).

 

[coolrunnings82]

Some day I'll get an R730XD but with how well my R720 does in every other aspect, it's not high on my priority list. It just sucks that they would make it PCI-E Gen2 when the board and chips support Gen3! Bah!

 

[David Lee]

Once you upgrade your CPUs of the R720 to Xeon E5 V2, the PCIe will automatically switch to Gen3. I have two of these Dell R720, one with 2 x Xeon E5 V1 and one with 2 x Xeon E5 V2. I can see that one is running PCIe at Gen 2 and the other is running PCIe at Gen3.

 

[BeTeP]

And unfortunately, the R720 can not be upgraded - the card/cables used for connecting the front slots in the R730XD use a different style connector (mini-SAS HD).

R720 can be upgraded just fine. You just need to replace the whole kit - PCIe switch card + cables + backplane. You can keep the cage.

Once you upgrade your CPUs of the R720 to Xeon E5 V2, the PCIe will automatically switch to Gen3.

You are talking about motherboard slots. But the PCIe switch (Dell P/N YPNRC) in question is based on PEX8632 which is PCIe 2.0 device.
I posted some more info in another thread
https://forums.servethehome.com/index.php?threads/dell-ypnrc-questions.26795/

 

[Dravor]

Once you upgrade your CPUs of the R720 to Xeon E5 V2, the PCIe will automatically switch to Gen3. I have two of these Dell R720, one with 2 x Xeon E5 V1 and one with 2 x Xeon E5 V2. I can see that one is running PCIe at Gen 2 and the other is running PCIe at Gen3.

I know this thread is mega old but, I'm in the same boat, and am running e5-2620v1 cpu's. You mentioned the PCIe Gen upgrading to Gen 3 with a switch to v2 cpu's. Is this documented anywhere else? This makes a lot of sense and I wish I had known.