Gabriele Svelto (gabriele.svelto.delete@this.gmail.com) on August 16, 2014 11:33 pm wrote:
> Not only that but with all these rate scores been thrown around it seems that nobody is paying attention
> to the single-threaded performance these cores will offer. One of the huge upsides of the low-power E3s
> is that they can pretty much all turbo to within 70-80% of the top frequency of the highest, most expensive
> bins. That means you get up to 70-80% of the single-threaded performance of the state-of-the-art as far
> as single-threaded performance goes. So how fast are these ARM cores going to be when running a single
> thread? I think that's a very important question because while it's true that low-power Xeons are bought
> with throughput in mind it's also true that they can still guarantee very fast response times in the
> face of serial code sections and that's very important in the server market IMHO.

Traditional server applications are always multi-threaded and capacity calculations therefore are be based on base frequency. Targeting a minimum response time for maximum expected application usage, memory foorprint, average CPU load, etc. etc. If the application usage is less (e.g. during night time), the turbo frequency may kick in and users may see quicker response times, but that is not something people really get excited about.

So I do not think single-threaded performance is very relevant.