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Amazon Makes It Almost Impossible To Calculate Their "Virtual CPU" Equivalent (informationweek.com)

Posted by timothy on from the n-divided-by-q dept.

dkatana writes: AWS started out defining its virtual CPUs as being composed of EC2 compute units, or ECUs, which it defined as an equivalent to a physical Xeon processor. However, a virtual CPU now looks suspiciously variable... A virtual CPU is whatever Amazon wants to offer in an instance series. The user has no firm measure to go by. From the article: [B]y doing a little math, you could actually compare what you were getting in virtual CPUs in EC2 versus Azure. Also by doing a little math, you knew how to compare one Amazon instance to another based on the ECU count in each virtual CPU. Microsoft didn't look too bad in the comparison. That is one of the casualties of the nomenclature change. I have searched for updated information on how a virtual CPU is measured and found nothing comparable to the definition of the 2012 ECU measure. I have questioned Amazon representatives three times between Oct. 27 and Dec. 21, and don't have much of an answer."

4 of 114 comments (clear)

  1. Re:Mostly irrelevant to most people by Anonymous Coward · · Score: 0, Insightful

    Microsoft is shit. PERIOD!

  2. Re: Quit whining by DThorne · · Score: 3, Insightful

    I'm not sure I'd call it whining - it's a significant investment for many to set up cloud computing the way they need it so I think it's a fair demand that if your gas station insists on measuring it's product in frackles that it give you a fair conversion rate for litres to frackles. My needs would be something predictable like rendering 3d images, so the first thing I'd be doing is measuring render times for the same image there and here. That's easy and relatively cheap to do, and the numbers scale directly, but I can see this being a serious issue for other uses.

  3. If you need well defined performance... by drolli · · Score: 3, Insightful

    then buy dedicated instances.

    I like micro instances/instances which do not occupy full physical processors at Amazon because of availability and price for low-impact/bandwidth applications. For all other use lambda or dedicated instances.

    Virtual CPUs are anyway difficult to asses - to me it may be very relevant to have the 1st level cache of the core which i run on undisturbed by other applications (since changing the cache hits is a big deal for specific numerical problems), and for you 20% more share of the CPU may be important.

    1% of computation time not spend in my task on a physical processor can do as much damage as 50% change in speed.

    A small side remark: the price for the different VCPUs also varies.

  4. Re:welcome back to the mainframe by known_coward_69 · · Score: 1, Insightful

    where can't you get high speed connections? NYC and LA are up to 300mbps and higher for time warner. other markets as well.