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More Cores, More DRAM, Means More Performance for 2014 Servers

Recently VMware enabled support for a number of hardware innovations that add more processor sockets, processor cores, and system DRAM to standard x86 servers. And we are beginning to see the performance benefits from it.

1.  Intel Xeon E5-2600-v3 Processor (codenamed “Haswell-EP”) support

“Haswell-EP” launched on Sep 8, 2014 and had immediate Day 0 support with vSphere 5.1 Update 2[2] that was available earlier.  With the launch of vSphere 5.5 update 2[1] the following day, there were 22 servers on the VMware Compatibility Guide supporting “Haswell-EP”[3] on that day.

The “Haswell-EP” generation system has a number of improvements over the previous generation system including: greater number of hardware threads (up to 18-cores and 36-threads per processor package and 72 threads for a 2-socket system), reduced virtualization overhead (vmexit round-trip time and better APIC virtualization), and DDR4 memory support. The “Haswell-EP” system also benefits from the significant improvements in storage and networking technologies made in the last year as well.

As a result, the “Haswell-EP” system should have measurable improvement in virtualization performance relative to the previous generation. Based on the limited VMmark 2.x scores available today, the first “Haswell-EP” score of 26.48 (Fujitsu PRIMERGY RX2540 M1) is an improvement of ~61% over the average score of 16.4 from the previous generation systems[4]. In the coming months with more VMmark scores being posted, we will see if this trend continues.

The performance improvement seen today with vSphere 5.1 Update 2 and vSphere 5.5 Update 2 is without benefit of the new instructions present in “Haswell-EP”. A Future release of vSphere will add support of these new instructions and the corresponding “Haswell-EP” Enhanced vMotion Capability mode.

I would like to thank Intel and our key server vendors for providing us the necessary “Haswell-EP” systems for VMware to complete this work and meet our Day 0 requirements for our joint customers.

2.  6-TiB (6144-GiB) DRAM Support

We snuck something else into vSphere 5.5 Update 2, support for 6 Tebibytes of DRAM[5]. Our customers have been telling us that they want to run a greater number of “large” VMs with multi-TiB vRAM on servers with 4 or more processor sockets. With 64 GiB DRAM DIMMs, a 4-socket Intel E7-v2 Processor (codenamed “Ivybridge-EX”) based system can have this much DRAM. And with 32 GiB DRAM DIMMs, an 8-socket “Ivybridge-EX” server can have the same amount.

Without the fantastic assistance of Dell Inc., support of 6-TiB in ESXi 5.5 Update 2 would not have been possible. Supporting this much DRAM requires many months of rigorous testing on a production-ready, stable server before we “freeze” the code for an ESXi release; this required our testing to start in December of 2013 when such platforms and DIMMs were not generally available. Dell stepped in at this early date and provided to VMware the Dell PowerEdge R920 with 6-TiB of DRAM. We used this rock-solid server as the reference for our large DRAM support over the many months of testing. We were also able to develop our large DRAM certification plugin on this server.

With the launch of vSphere 5.5 Update 2, the Dell PowerEdge R920[6] is already listed as supporting this much DRAM in the VMware Compatibility Guide — and you can be sure of this support because it was the reference. By the end of this week, VMware will also make the certification plugin available to other server vendors wanting to support 6-TiB on ESXi.

Of course, large DRAM support doesn’t stop here, and you can expect in a future vSphere release for even more DRAM to be supported.

3.  8-socket Support for Intel Xeon E7-v2 (codenamed “Ivybridge-EX”)

We are happy to announce that vSphere 5.5 and vSphere 5.1 Update 2 will support 8-socket “Ivybridge-EX” servers.  The 8-socket “Ivybridge-EX” allows support of 120 cores (240 threads) and up to 6 TiB DRAM using much cheaper 32 GiB DRAM DIMMs. We are awaiting VMmark results, but they should be encouraging.

Speaking of fantastic assistance, our partners IBM and Fujitsu each provided VMware with production-ready 8-socket “Ivybridge-EX” servers (IBM System x3950 X6[8], Fujitsu PRIMEQUEST 2800E[7]) so we could finish our internal qualification on these class of servers. (VMware already has support of 4-socket “Ivybridge-EX” servers, but we have been waiting for stable 8-socket servers for some time.) We were impressed with the stability of these 8-socket servers used as reference systems in our internal testing and you will be also. The IBM and Fujitsu reference servers will be listed on the VMware Compatibility Guide within days of this posting. Our other server partners should get the certification notice in the next day. By next week, you should see a number of such servers listed.







5.  2^40 = 1 Tebibytes ~= 1.10 Terabytes, see





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