Intel's future Sandy Bridge Xeons exposed
x64 iron choices galore
Exclusive The ongoing x64 server chip war is going to heat up considerably in the third quarter, with both Intel and AMD firing off new processors for midrange server buyers. And we now have a few more details about Intel's future "Sandy Bridge" Xeon platforms and the chipsets that drive them.
Processor socket and chipset transitions are a big deal, and if server makers don't get behind you – perhaps because there is a Great Recession on and they want to cut back on development costs and bet on the surest things to sell in the market – then you have a big problem. Like what AMD had in late 2009 with the delivery of its first home-grown server chipsets – the "Fiorano" SR56X0/SP5100 combo  – and the Opteron 4100s in their C32 sockets  and the Opteron 6100s in their G34 sockets , which make use of these chipsets, coming out the following spring.
AMD had two different sockets and three different chipset variants to appeal from everything from low-powered single-socket servers all the way up to four-socket boxes with lots of memory and I/O expansion. The technology was good, and the price was right. It just so happened to coincide with a recession and a lot of companies betting on Intel's "Nehalem" generation and its new bus architecture.
AMD does not have to go through painful processor socket and chipset transitions, as it had to last year to its financial chagrin. But it does have a new line of Opteron 4200 and 6200 chips coming out based on the "Bulldozer" cores and a ramp of GlobalFoundries' 32 nanometer wafer baking processes to contend with, so it is not easy skating for AMD, either. Still, AMD has been gloating a bit  that the Bulldozer ramp will be easier and Intel has to juggle a bunch of things at the same time with the Sandy Bridge transition.
That's true enough, of course. It is Intel's turn to have to change up sockets and chipsets with the Sandy Bridge Xeons, but Intel's 32 nanometer processes are fully ramped for its server chips, so that is not an issue. And because Intel has to change up server platforms anyway with the Sandy Bridge Xeons, the chip giant is taking the opportunity give server makers more options to accommodate the divergent needs of server makers.
Take a gander at this roadmap, which lays out the server platforms that are coming down the pike:
Intel already launched the Sandy Bridge-DT processors back in March, which we now know as the Xeon E3-1200 chips  and which are mostly aimed at micro servers – machines with one socket and minimal memory and peripheral expansion. The Xeon E3 processors plug into Intel's Socket-H2 chip socket, also known as the LGA-1155 (which gives you the pin count and style of socket-to-chip interconnect, in this case a land grid array). The combination of the Xeon E3 processor, the H2 socket, and the "Cougar Point" C202/204/206 chipsets is known as the "Bromolow" platform.
'Romley' for a premium
Looking ahead to 2011 and early 2012, Intel has a number of different variants of the "Romley" platform aimed at different parts of the server racket coming out. A Romley platform designed for "premium" single-socket and "entry" two-socket servers will be comprised of the "Sandy Bridge-EN" Xeon E5 processor, the Socket-B2 (LGA-1356) socket, and the "Patsburg" C600 chipset. A variant of this two-socket Romley platform will be aimed at small form factor servers – think half-width two-socket motherboards used in blade and cookie-sheet servers.
A beefier version of this two-socket Romley platform will come in uniprocessor and two-socket variants and will sport the Socket R (LGA-2011) socket and make use of the Sandy Bridge-EP variant of the Xeon E5 processor. Further up the stack, Intel is cooking up a four-socket Romley platform that will use the high-end "Sandy Bridge-EX" processors. The former Romley platform will use a Patsburg chipset, while the latter one will use a kicker to the current Boxboro chipset. As you can see, the high-end two-socket and low-end four-socket servers of the Xeon future will use the same Socket R socket, which will make life easier for server makers.
The big differences between the midrange Romley platforms have to do with what is activated on the Patsburg chipset and what is not, according to documents that El Reg has been able to get its hands on:
The Romley servers based on the Socket-B2 socket will be able to scale up to eight Sandy Bridge cores per socket, but the B2 sockets only have one QuickPath Interconnect (QPI) link between the two processors on the board and only three memory channels per socket with two DDR3 DIMMs per channel (DPC in the chart). The Patsburg chipsets used in the Socket-B2 Romley machines will implement 24 PCI-Express 3.0 lanes per socket, which can be carved up in a number of different ways.
The fatter Romley Socket-R machines will take on the full Sandy Bridge core count of eight cores, but there will be two QPI links between the sockets for improved performance on SMP workloads, four memory channels per socket and three DIMMs per channel for higher memory capacity and bandwidth, and 40 PCI-Express 3.0 lanes per socket for peripheral expansion. GPU coprocessors will eat this I/O for lunch.
There are a mix of LAN-on-motherboard (LOM) Gigabit and 10 Gigabit Ethernet options for networking. The industry has been waiting for 10GE ports on motherboards, and with the Romley platforms, Xeon server makers will finally have them. This will make the cost of 10GE networking come way down and spur the adoption of 10GE switches in the data center.
A 'Patsburg' for every need
A lot of the variation that Intel is baking into the Romley platform is coming from the Patsburg chipset, which is coming in four different flavors, the C600-A, C600-B, C600-D, and C600-T. Here's how the different peripheral features of the Patsburg variants stack up:
By making a variable Patsburg chipset, Intel can deliver different functionality at different price points and do a better job of competing against AMD, which is trying to win hearts and data center budgets straight out on low pricing with two different processors in two sockets and three chipset variations. If Intel can best meet the needs of different server customers by having a range of I/O options – allowing server makers to only put the features customers absolutely need and will pay for into each box – then Chipzilla has a good chance of deflecting what we assume will be a very aggressive Opteron 6200 in the summer and then Opteron 4200 launch later in 2011 or perhaps early in 2012.
In any event, the Patsburg-A chipset supports four 6Gb/sec SATA ports for disk drive or solid state drive storage. The Patsburg-B chipset adds support for 6Gb/sec SAS peripherals. Both of these Patsburg variants seem to use the x4 DMI Generation 2 interface that Intel created for linking on-chip HD Graphics coprocessors to the CPUs. The Patsburg-D chipset adds four more SAS or SATA ports and a PCI-Express 3.0 uplink to the CPU to carry the extra load. All three of these Patsburg chipsets offer software-based RAID 0, 1, 5, and 10 data protection on the SATA ports and RAID 0, 1, and 10 protection on the SAS ports.
If you want RAID 5 protection on your SAS drives, you need to buy a machine with the fourth Patsburg-T variant. The T variant of the C600 chipset will also support non-volatile storage (NV-SRAM), and it seems reasonable that this will be a cache for the RAID 5 disk arrays implemented by the chipsets. ®