2012-04-08

Sandy Bridge-EP platform

While Intel's Ivy Bridge CPUs are on the horizon I happened to get Sandy Bridge-E sample on my hands. It is Sandy Bridge-EP 4S more precisely. This CPU will become a member of Xeon E5-4600 series when they will be released and they are primarily intended for 4-way servers. My sample is packed into 2011-land FC-LGA package and works on LGA 2011 socket.  Despite its intended purpose to be a server CPU it can be used on desktop perfectly too. My sample's s-spec is QAFF and its specifications are as follows:
  •  3GHz frequency (30x multiplier), max 3.3 GHz on turbo boost
  • 10 MB L3 cache
  • 4 cores, 8 threads
  • 32 nm 
  • 130W TDP (not confirmed)
  • support for AVX, SSE4.2 and other modern instructions and features like in most sandy bridge cpus.
So I would call it "low-end" or "mainstream" CPU on targeted platform and it is comparable to Core i7 3820 desktop CPU by specs but has much less frequency (3820 clocked at 3.6 GHz by default). CPU multiplier is locked. 

There is always a risk if you buy engineering sample CPU. Firstly, no motherboard will support it officially and you need to find at least some information on supported ones (mostly you need to know at least one supported motherboard from specific manufacturer and then compare their motherboard specifications, BIOS and CPU support to make decision if you are not satisfied this the one you found as compatible). In the worst case you probably will be able to sell incompatible motherboard for some little loss (of course, if you don't live in the small country like me). Secondly, you won't have any warranty. If CPU will die, nobody will replace it. Finally, you can't write a lot about it until official CPUs are released (Intel doesn't like leaked CPUs and can take actions on sellers and on even on bloggers). Nevertheless this CPU has more or less the same core as other Sandy Bridge-E(P) CPUs so you can always imagine performance by reading articles on similar items. When you consider all these factors and still decide to buy a CPU you should be ready to lost the money in the worst case. However, it is still aren't very risky decision in my experience. CPU is probably one of the most reliable parts compared to other computer parts. If you spend enough time to check motherboard compatibility and have enough sources to prove your decision this move becomes even less risky. On the bright side ES CPU can be purchased for less money than production chip (not applicable for first samples of new architecture or platform or very rare collectible old items).

Personally it is my second engineering sample CPU (used for actual computer, not for collection purposes). First one was Xeon E5540 ES Q1E2 Nehalem CPU. Unfortunately, X58 platform wasn't very satisfactory for my purposes and I replaced it with Athlon II X2 235E on AMD 780G platform. It was great platform until Jetway JNC81 motherboard died. Jetway replaced it with JNC84-E but it wasn't so friendly with NetBSD. What is more, I wanted more performance for compiling, folding and other tasks. Though, I still didn't plan to change computer initially in the near future but I bought Sandy Bridge-EP CPU at a reasonable price and decided build the platform on it.

I wanted to go as cheaply as possible because of this I bought relatively cheap ASRock Extreme4-M motherboard, Thermaltake Contac39 CPU cooler and reused some parts from retired mother's Phenom II X2 555 computer (like RAM and graphics card) and my computer (HDD). I plan to add two more RAM modules to make them work on 4 channel mode but currently system works on 2 channel mode. I also would like to get less powerful and more power efficient graphics card (GeForce GTS450 now) but it depends on how successfully I will sell my parts on second hand market. Nevertheless the platform still cost quite a lot as X79 motherboards are pricey and even the cheapest one cost about double of what I spent on one motherboard typically. Extreme-4M wasn't the cheapest one but Intel boards didn't have enough sources to prove compatibility (ironically) and Extreme-4M was more appealing for me than Extreme-3 which one was the cheapest solution from ASRock line.

So my current setup is:
System setup went without big problems. CPU was recognized as GenuineIntel 3GHz. It works on 1.2GHz on idle. Motherboard uses modern UEFI BIOS. I needed to set 1600 MHz for RAM manually as they worked as 1333MHz by default. No other big changes were needed. Fedora 16 booted without visible problems and worked perfectly. NetBSD wasn't so good. It booted better than on JNC84-E platform (it typically didn't load on first try and needed repeated boot command in the bootloader. This problem disappeared by surprise for me), but NIC (Broadcom BCM57781) didn't work correctly (as result no internet and network), GTS450 graphics card wasn't supported too (X.org failed to start). Keyboard needed reconnect on the first boot but problem didn't reoccur on other times.  So currently I need to solve these issues somehow. On the other hand I expected more worse situation as platform was relatively new. These two problems are quite small and solvable. Of course, USB3.0 is not supported on NetBSD but I don't have any devices anyway. The whole platform uses 86-92W on idle and ~160W on full CPU load (by folding@home). For comparison unlocked 4 core Phenom II X2 555 used around 200W and more with the same graphics card and RAM.

QAFF ES 3.0 GHz