With the ever-increasing core counts on modern CPUs, dual-socket systems are no longer as essential for high-end workstations as they used to be. Which is a good thing for various reasons. Not only can you do away with expensive, complex motherboards, but everything from power efficiency to software compatibility is much simpler if youíre using a single CPU package.
Unfortunately users that need extremely large amounts of RAM have still been limited to relying on dual-CPU systems, since these systems have enough memory controllers between both CPUs to address massive amounts of memory. Intelís Xeon M series of CPUs change all of that, but it does come at a price.
How Much RAM Are We Talking Here?
Letís get the main selling point out of the way. If we look at the Xeon W series of CPUs, youíll notice that standard models can address up to 1 TB of RAM. Thatís probably enough for most people, but in many data-heavy workloads it just wonít cut it. If you opt for the ďMĒ version of the CPU instead that amount doubles.Two terabytes of memory is a major jump, but before you jump for joy we have to talk about price tags.
Itís How Much?
In the Xeon W 3200 series of chips, there are three ďMĒ models: W-3245M,W-3265M and W-3275M. If you compare them to their non-M equivalents, youíll see that core countries, clock speeds and TDP are all identical. Yet, the price difference in each instance is $3000. Thatís a huge chunk of change, so you really need that extra terabyte of memory to justify it.
Then again, the cost of a dual-CPU system adds up quickly. Bigger PSUs, much more expensive motherboards, double the cooling,etc. In some cases it will make more sense to simply buy two CPUs and also benefit from more cores. However, if the total additional cost of a dual-socket system is less than the price premium of the M models and you have no use for additional CPU performance, itís an elegant solution.
The W-3200 Goodness
Itís worth taking a minute and talking about the Xeon W 3200 series chips themselves. These CPUs are noteworthy for other reasons as well. All models, M or not, have 64 PCIe lanes, making them exceptional for multi-GPU setups. They also have much higher core counts, which is another reason such a system might work out cheaper overall than a dual-socket configuration.
While the price premium for the M series of chips is certainly staggering, for many users this will be the optimal solution, especially considering that Intel supports mixed RAM configurations. Making it possible to start with a smaller amount of RAM and work up to higher numbers (past 1 TB) using different module configurations.