Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror
×
Cloud Virtualization Hardware

Amazon Makes It Almost Impossible To Calculate Their "Virtual CPU" Equivalent (informationweek.com) 114

Posted by timothy 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."
This discussion has been archived. No new comments can be posted.

Amazon Makes It Almost Impossible To Calculate Their "Virtual CPU" Equivalent More

Amazon Makes It Almost Impossible To Calculate Their "Virtual CPU" Equivalent

Comments Filter:

  • Totally true (Score:1)

    by Anonymous Coward

    In fact Amazon doesn't know themselves... I have asked them to compare to the i7 series and they simply don't have a clue.

    • when I did some testing a while back. $20 a month would get you processing of a crappie mobile you could buy for $50. Amazon has never had good cpu.

      so it's probably more that they don't want to say.

      anyone who's benchmarked them against alternatives has nothing good to say.

      http://openmymind.net/Why-I-Di... [openmymind.net]

      • Re: (Score:3)

        by lgw ( 121541 )

        That's a good link. My real complaint about AWS is what's mentioned at the end:

        It also feels like a lot of services are stuck at version 1.0, lacking that polish and continual improvement

        This is what annoys me. SQS is a good 1.0 version of message queues, but the features are the just above the minimum you could possibly call a message queue. DynamoDB is a good 1.0 version of a NoSQL DB, just above the minimum you could possibly call a NoSQL DB.

        These services are years old, but look like what most software does at version 1.1 or so: minimal features, no glaring bugs, but nothing great either.

        I can't say anythi

        • each insrance is one of who knows how many virtual machines running on old xeons.

          • Re: (Score:2)

            by lgw ( 121541 )

            Right, but they clearly promise you a number of cores. The easy assumption is that the cores aren't oversubscribed, and none of the docs suggest they're oversubscribed, except the docs for T2 (seems like it must be). Can't tell for sure, of course, unless someone can find something definitive from Amazon.

            • what they promise is by "virtual core".

              that has no L1/2/3 cache.
              and will be balanced on the machine based on actual cpu cycles (my "real" 3.5ghz cpus can "turbo mode" to nearly 7ghz on heavy loads - Linux cpu-governor)

              it's an extreme version of the old hdd spec lies.

              http://tiemensfamily.com/TimOn... [tiemensfamily.com]

              300...

              compared with 10s of thousands for a "real" core.

              • Re: (Score:2)

                by lgw ( 121541 )

                I can't make much sense of your post, and the linked article is a bit confusing as well. But if the claim is that the 2 cores from an m1.large are about what you'd expect from 2009, I can totally believe that - the m1 instance is pretty old. I'd expect them to be sub-2-GHz Xeon cores. Xeon is usually damn slow compared to the consumer cores from the same year, and it's not sensible to compare Xeon performance to consumer performance (or, at least, it's Intel's brain damage, not Amazon's).

                From the docs, m

  • Mostly irrelevant to most people (Score:4, Interesting)

    by AmiMoJo ( 196126 ) on Friday December 25, 2015 @06:42AM (#51181589) Homepage Journal

    Most people don't care about the exact performance, so it's not with spending the money and effort to precisely define or guarantee it.

    Amazon is generic and cheap. Microsoft has really good integration with visual studio and .NET. Those are the factors people choose by.

    • Re: (Score:1)

      by Anonymous Coward

      Considering that most modern CPUs have performance counters and such, there is no excuse not to be able to measure it, particularly when you are charging for it. How big is this house you want to sell me? Well, somewhere between 100 and 300 sq. m., nobody cares, so why are you whining about it, am I right?

      • CPU built-in performance counters are as reliable as the size of the fish catch described by your alcoholic uncle.

        • Re: Mostly irrelevant to most people (Score:5, Funny)

          by TheReaperD ( 937405 ) on Friday December 25, 2015 @07:43AM (#51181663)
          After rereading my post, I realized I needed to post a clarification for the easily offended: "your alcoholic uncle" is used as a generic example and not referring to the AC's uncle.

          • Re: (Score:2)

            by Dunbal ( 464142 ) *
            Fuck the easily offended politically correct cunts. They are useless anyway.

          • Re: (Score:1)

            by phorm ( 591458 )

            I try to use the phrase "one's alcoholic uncle" which is less likely to be misconstrued as personal. :-)

    • This behavior is what I (and others) predicted when this whole "cloud" stupidity began: as providers become more entrenched, the prices and complexity slowly increase. Those who become dependent on this particular brand of idiocy will be taken to the cleaners.

  • I read this a they're worth whatever they say it's worth (at the moment) and you're going to whine and complain about it but, not do anything about it. Until they start loosing a large dollar value of customers over it, they're not going to fix it.

  • what a surprise (Score:3)

    by climb_no_fear ( 572210 ) on Friday December 25, 2015 @07:19AM (#51181627)
    that the "Cloud" is nebulous....

  • Imho there is only 1 valid measurement for cloud solutions, how much will certain performance cost you. And you can only really find out by testing it for _your_ specific goal. Some apps require more cpu, others more disk, others more ram... there's no single number to indicate your price/performance index.

  • If you need well defined performance... (Score:4, Insightful)

    by drolli ( 522659 ) on Friday December 25, 2015 @07:45AM (#51181675) Journal

    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.

    • This is exactly the problem, and solution.

      From a computer science standpoint, modern algorithms that rely on single-thread speeds are obsolete and should be avoided for new development. From a sysadmin perspective, CPU speed is the least important metric compared to the rest of the system components. For project management, the system management toolset and feature support should be the prime concern.

      Amazon's never really tried to hide the fact that their hardware is dissimilar behind the scenes. That will

  • beg for CPU time and be happy when the admins throw you a little bone just like back in the 70's

    • Re: (Score:1)

      by Anonymous Coward

      This is a scam by ISPs. They won't give you a high-bandwidth uploading network connection at your home or office. So you have to pay rent to run some slow computer at some remote facility.

      It's not 1990 anymore... why can't you host a server at your own place.

      • Re: (Score:2, Insightful)

        by known_coward_69 ( 4151743 )
        where can't you get high speed connections? NYC and LA are up to 300mbps and higher for time warner. other markets as well.

        • Re: (Score:1)

          by Anonymous Coward

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

          The first commonly used modems were a *thousand* times faster than that. Connections here in the US are very slow, like the typical 1.5 Mbps T1 or DSL connections in the Seattle area for businesses, but the claim that it takes more than three seconds to transmit a single bit, is a lie.

  • I was considering using AWS... but it seemed to complicated with their calculator to get any kind of estimate of what it would cost me I went with dedicated servers instead.
  • Big deal. Try asking azure support about licensing and they will flat out say I don't know. Assuming you bugged them at least a half a dozen times about the same questions beforehand.
  • > "A virtual CPU is whatever Amazon wants to offer in an instance series." No. The vCPU (Virtual CPU) aspect of an AWS EC2 Instance is the county of virtual cores that are exposed to an OS. In desktop computers, a quad core Intel CPU will appear to have four courses when looked at from inside the OS (my go-to way to count them in Linux is to run top and press 1). A quad core hyperthreaded Intel CPU will appear to have 8 cores. The vCPU metric simply tells you what the OS will show you, and tells you how

    • Re: (Score:2)

      by pgn674 ( 995941 )
      Ugh, sorry about formatting. Here, I think this is right:

      "A virtual CPU is whatever Amazon wants to offer in an instance series."

      No. The vCPU (Virtual CPU) aspect of an AWS EC2 Instance is the county of virtual cores that are exposed to an OS. In desktop computers, a quad core Intel CPU will appear to have four courses when looked at from inside the OS (my go-to way to count them in Linux is to run top and press 1). A quad core hyperthreaded Intel CPU will appear to have 8 cores. The vCPU metric simply tells you what the OS will show you, and tells you how many processor threa

  • The old VAXen that DEC sold came with a measure called VAX Units of Performance (VUP's). You bought stuff with a certain amount of VUP's rather than raw performance specs. Now Amazon is selling some Amazon-specific measure of performance that benefits them more than us. More signs the cloud is just re-inventing the mainframes and minicomputers of old. Cheaper, faster, more flexible, and so on for sure. Same concepts, though, plus what it seems is the same bullshit. :)
  • Maybe its all meant to be like mobile phone plans. So complicated that no one can workout which better or cheaper

Slashdot Top Deals

"I've finally learned what `upward compatible' means. It means we get to keep all our old mistakes." -- Dennie van Tassel

Close