Balancing Power, Price, and Performance in the Server CPU World

Conclusion

A 2P server CPU for less than $100 sounds great, but if that quad-core CPU—the Opteron 4122—consumes more than CPUs that are more powerful, it's probably a bad idea for a server. Since servers run 24/7, electricity and cooling costs contribute almost as much as the CAPEX costs to the TCO.

The Tyan YR190B8228 for example is a very inexpensive server, with a barebone price of only ~$1500 for two servers. Add to that the CPUs, the storage card that accesses the external storage, a few SATA disks, and lots of RAM, and those two servers will cost anywhere between $2500 and $4000. Saving $100 per CPU or $400 per two servers is less than 15% of the CAPEX costs. Saving a few hundred dollars just to waste them later on more electricity and cooling costs just doesn't make sense.

AMD targets those running "Small Business Servers", but even SMEs do not turn off their servers very often. That means that the Opteron 4122 and 4130 only have a place in a cheap workstations that are on eight hours per day. In that case, the 2.6GHz Opteron 4130 ($125) might prove to be a better option than using a low-end Phenom X4. However, we advise against using these CPUs in any 24/7 server.

The Opteron 4170 HE is a much better deal. It is worth investing a few dollars more in getting an HE Opteron instead of a non-HE Opteron 4000. A low-end Xeon E560x series CPU is also viable.

The Opteron 4000 HE consumes very little at idle, which is good for SMB servers as they idle a lot. As a low budget virtualization server, it consumes about 20% more power than the Intel L5630 but saves you almost $400 per CPU. It does this while performing "good enough" in many situations.

Concerning the Opteron 4162 EE, we agree with AMD that this is a good CPU for hosting and cloud environments, but not always. The Opteron 4162 EE makes sense for "budget hosting'", which is a pretty large market. (By "budget hosting" we mean that people accept the possibility of lower availability as they just want to pay as little as possible to get their website on the internet, i.e. Tier 3)

The moment you start looking at "enterprise class hosting" (i.e. Tier 2 and better), where the hosting providers invest in redundancy features to guarantee higher availability, the Xeon L5630 is the CPU to get. The extra capital investment in more expensive CPUs will be noise in the TCO calculation, and the Xeon consumes slightly less while offering up to 40% more CPU power.

Our conclusion is that if you are looking for very cheap server CPUs, the Opteron 4170 HE (2.1GHz) and 4174 (2.3GHz) are very interesting options. Resist the urge to go for the Opteron 4xxx without the HE markings. The moment performance comes into play, the Xeon L5630 is the performance/watt champion, without any doubt. However, there are situations where you are completely power limited and care very little about CPU performance as the number of VMs is limited by memory or disk access I/O. In that case the Opteron 4162 EE offers the lowest power consumption for the lowest price.