Memory choices for Cisco UCS B200 M3 Blade Server (Romley)

This server has 24 DIMM slots for a total of 384GB (using 16GB RDIMMs).

However I cannot find any docs outlining the speeds achievable at 1 DPC, 2 DPC, 3 DPC (as are available from IBM and others).
Cisco UCS B-Series Blade Servers
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Cisco UCS B200 M3 Blade Server
24 DIMMs – 384GB

Cisco UCS earlier used an ASIC-on-motherboard (Catalina ASIC) approach for “load reduction” – that they are not using on the B200 M3 (see below).

If so, their speeds achievable may be similar to what the other OEMs are delivering.

Cisco UCS latency penalty using Catalina ASIC-on-motherboard approach

The Cisco UCS solution (using ASIC-on-motherboard approach) has a “6 ns latency penalty” compared to RDIMMs (just read this figure on a blog – not sure of it’s accuracy).

Cisco UCS has now switched away from their earlier ASIC-on-motherboard solution which suggests they are now going to be using the LRDIMM/HyperCloud type of solutions (which are ASIC-on-memory-module) for “load reduction”.
Cisco outs third gen UCS blades and racks
California dreaming
By Timothy Prickett Morgan
Posted in Servers, 8th March 2012 16:48 GMT

The B200 M3 blade supports the Xeon E5-2600s with four, six, or eight processor cores and supports up to 384GB using regular, registered DDR3 memory sticks in 16GB capacities. The Cisco spec sheets do not say it supports LR-DIMM memory, but the presentation I have seen says the box does support 768GB, and that means 32GB sticks are coming – and for all the other vendors I have spoken to, getting to the full 768GB capacity has meant using LR-DIMMs.

What I can tell you is that Cisco has not used its own Nuova memory extension ASIC, used on some of the existing B Series blades and C Series rack servers, to boost memory capacity by as much as a factor of 2.7. Satinder Sethi, vice president of Cisco’s Server Access & Virtualization Technology Group, said that none of the three Xeon E5-2600 machines launched today use the Nuova memory-stretcher ASIC.

Here is an earlier article comparing the Cisco UCS approach (ASIC-on-motherboard) vs. Netlist’s (ASIC-on-memory-module):
Netlist goes virtual and dense with server memory
So much for that Cisco UCS memory advantage
By Timothy Prickett Morgan
Posted in Servers, 11th November 2009 18:01 GMT


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