m.2 M.2-SSD in Display computer: good idea?

[Michael Scheck]

Hi all, 

I have been reading about M.2-SSD that connect through PCIe and can read 2-3GByte/s. I tried one, the speed is really good. Now, is it a good idea to have this device in a WO-display computer or should one rather stick to SSD-Raid0 thru SATA? 

 

Regards, 

 

Michael

[jfk]

Very good idea, many users are utilizing M.2 drives for the media drive.

[Thomas Leong]

Buyer Beware!

Not all M.2 slots provided by motherboard manufacturers are made equal.

 

To get the 2-3+GB/s Sequential Read Speed one desires, the slot must be capable of 32Gbits/s transfer speed, or PCIe Gen3 x 4. Some are only capable of 10Gbits/s (Gen2 x2). In particular, the ASUS X99M-WS (a workstation class board), the Gigabyte GA-X99M Gaming 5, and the EVGA X99M Micro (the Micro2 upped the slot to 32Gb/s). One would naturally think that a HighEndDeskTop X99 cpu and motherboard with its plentiful PCIe lanes over the enthusiast class Z, H or B series would have that speed without question, but that is not the case with some motherboards.

 

The above-named example motherboards may have been limited to mATX, but there are ATX motherboards with only 10Gb/s M.2 slots as well. So do your research before buying.

 

Thomas Leong

[DavidPatrick]

We have started upgrading our machines to M.2 drives and noticed a 3x jump in HD read speeds over our SSD RAID-0. To Thomas' point, when I first installed the M.2 drive directly to the motherboard, I didn't get much speed bump. However, by attaching the drive to a PCIe adapter card, I was able to take advantage of the full PCIe 3.0 x4 speed. The adapter cards sell for about $20 USD, so it's not a big investment if you're buying an M.2 already.

 

Just another option if you don't have a fast M.2 port on your motherboard. Some motherboards are also configurable (based on where other cards are installed, BIOS settings, etc) so give your MB manual a good read also.

[jochri]

When pushing m2 disks to the extreme with tiff sequences we find them overheating soon. So remember to keep them cool!!!

On some machines we use M.2 SSDs in raid configuration but on the normal machines we use INTEL SSD 750 or Micron 9100 PCIE SSDs, sometimes in Raid 0.

These are made for 24/7 usage and are way more reliable then M.2 disks also because of overprovisioning of storage space.

Depending on the configuration they will give you 2500 - 6000 MB/s of data throughput .

 

When ugprading to fast SSDs you should also consider moving to 10G ethernet which, from my point of view, should be standard by now!

Once you used Watchout with 10G you never want to go back! 10G infrastructure also is very much affordable nowadays.

 

By the way Watchout on Win10 clients give us a transfer performance of tiff sequences which is 3-4 times faster then on Win 8.1 clients in the same hardware configuration.

Transfering files through windows 10 itself to Win 10 and Win 8.1 clients shows no difference...

[Claude.Rivet]

M.2 drives are actually the way to go in display computers but there are a few things to keep in mind

 

1- Number of lanes: PCIe bus have 1GB per lane of bandwidth (roughly), it is important that you do your bandwidth calculation before building your computer and it is important you manage those lanes appropriately else you will have less performance from M.2 drives than from a normal SSD. Some slot share their bandwidth with the M.2 slot, if you install your graphic card in slot 1 for example and your M.2 drive in M.2 slot 1 they will compete for bandwidth and dramatically reduce your performance. Your motherboard documentation should layout how lanes are distributed. That also brings us to RAID1 M.2 drives, it's a very bad idea on most motherboard for the reason stated, however some PCIe card can fit more than 1 M.2 drives and raid them, this is the way to go, this way you have dedicated lanes for your storage because you aren't using shared lane slots. That also means you will have to reduce overall bandwidth usage for your machine, distributing your lanes appropriately becomes very important.

 

2- M.2 drives are NVMe SSDs, the one with insane performances at least, which mean they are not secure or stable and it means the performances will degrade with time, after 3years I get about 2/3 of my original bandwidth on my Samsung 950pro. It is important you have a backup system in place, personally I use an internal hidden drive and using one scripted keyboard key I backup my M.2s on this drive whenever my show reach a milestone in programming. SSD fails, they will, it's not a matter of "if" it's a matter of "when", be prepared.

 

3- Do NOT use an M.2 drives for your system, the CPU overhead is not worth it and in my experience it is far less stable, don't ask me why I still haven't figured that out but IF the motherboard can boot from M.2 corruption is more likely to occur on system drives than data ones.

 

4- HAP is ultimately limited by your drive bandwidth but you have to make sure there is still bandwidth available for the exchange between the graphic card (HAP is decoded by your GPU) and your drive and the system memory, so 5GBps becomes 20GBps because you use your lanes to read from drive, send to the card and read from the card in main memory where Watchout renders the scene for example, if your source is an input card count 4GB per HD input (according to Datapath documentation).

 

That's about what I can think of right now but basically using M.2 is not a simple switch like going from HDD to SSD, your need to manage ressources.

 

hope this helps

[Jonas Dannert]

Thanks for the great insight, Claude! 

 

/jonas

[Michael Scheck]

Hey guys, 

thanks a lot. Great information, very valueable!

Michael.

[damyitaly]

the bootleneck for the low NVMe performances  are the  Pci-Ex Lines managed from the processor and the CHIPSET.

  On real workstations, every processor must manage 40/44 lines PCI-EXPRESS.

Consumers processors manage 24 lines and the bottleneck is sure!

For this reason real professional workstations are configured with two Xeon E5 2600 processors on socket LGA 2011 v3 and chipset C612. The second xeon processor is used for Amplify the pci-express lines.

Workstastions Entry level/low cost are made  with a single processor extreme version as I7 6950x  on socket LGA 2011 v3 and chipset X99, or the new i9 family on sk LGA 2066 and chipset X299.

In the workstation/server  motherboards manual, you can found PCI-Ex slots  connected directly with CPU, and the lines PCI-EX connected with chipset.

Primary expansions cards with very high bandwidth as  High End GPUs, storage NVMe, and raid controllers, must  be linked on processor bus. 

Scondary expansion cards with low/medium  bandwidth on lines linked with controller bus.

Another suggestion is about RAID 0 with SSDs(SATA,NVME)... Never do this configuration! With RAID 0 TRIM and garbage on SSDs are disabled from S.O.

With RAID0 SSDs max performances are limited to 4000 writes! If you want RAID 0 you need SAS SSDs and SAS HW conroller DC class.

The last suggestion is about GPUs. Never use high end consumer/gaming GPUs on workstations, Consumer GPUs are streams limited to 2. Real  GPU for workstation are all professional GPUs with stream unlimited  and sync card support

In general workstations and server configuration isn't simply as consumers or gaming PCs. Don't try to assembly yourself if you don't know computer architecture.

[hilleli]

Thanks. I didn't knew that Consumers processors manage 24 lines
It helped me a lot