Original URL: http://www.theregister.co.uk/2012/03/07/adaptec_raid_roc_pcie_gen3/

Adaptec trickles RAID RoCket fuel into new Xeons

PCIe 3 is I/O gulper

By Chris Mellor

Posted in Storage, 7th March 2012 20:03 GMT

CeBIT It all came together at CeBIT for Adaptec with a searingly fast 6.6GB/sec supply of data across a PCIe gen 3 bus to a Xeon E5-2600 server – twice as fast as gen 2 PCIe servers.

The configuration for the demo used a prototype SRVc RAID-on-Chip (RoC) card from Adaptec, now owned by PMC-Sierra, hooked up to a server using Intel's shiny new Xeon E5-2600 processors via this PCIe gen 3 bus, which runs at 8 gigatransfers/sec rather than gen 2's slightly more pedestrian 5GT/sec.

Twenty-four 6Gbit/s SAS ports come out of the back of the SRVc and 22 of them hooked up to Seagate Pulsar.2 SSDs. Each of these 2-bit MLC drives can do 370MB/sec sequential reads and 200MB/sec sequential writes. We're not told the capacity of the drives which start at 100GB and go up to 800GB.

If they were 800GB then total capacity would have been 17.6TB. These SSDs do 48,000 random read IOPS and 15,000 random writes. Twenty-two of them would collectively output 8.14GB/sec sequential read data if driven at full speed.

Bearing in mind that Dell is using hot-swap Micron PCIe gen 2-interface SSDs in its 12th generation servers, we can see the possibilities. PCIe gen 3-equipped, Xeon E5-2600 servers will have an awesome capacity to suck in data. Interfacing them to disk drive arrays would seem to be putting them on a starvation diet. They are going to need flash because that's the only storage medium that can keep up with their gargantuan appetite for data.

Marvell has got to be planning a PCIe gen 3 controller already. Seagate will know-all about Micron's new PCIe-interface SSD and will surely be thinking of adding its own PCIe interface to its Pulsars. A Xsigo spokesperson said: "We won't be doing PCI-E sharing, no (as it doesn't work well), but InfiniBand 56Gb and 80Gb need PCI-E v3 for bandwidth: that's due soon."

The message for storage array vendors is to do as EMC, NetApp and Nexsan have done and get a flash front end for your storage offering. For the flash array, SSD and flash card vendors, a PCIe 3 interface will become mandatory if you are going to be up with the front runners in the server flash speeds and feeds race. ®