System i 515 performance considerations

If you’re intending to buy a System i 515, there are a few pitfalls IBM has built into the product to lower it’s price a bit.

The model usually advertised comes with 2 70GB disk drives, without any console, 1 GB of RAM, and a 4mm 36/72 GB tapedrive.

Here are the pitfalls:

  • i5/OS is very I/O intensive. Two 70GB disks will give your a very crawling system if your datasets don’t fit into RAM. Make that you have at least 4 disks – and use RAID5 if possible. Mirroring only makes sense if you can afford enough disks (8).
  • i5/OS also needs enough RAM because of the first point. I would consider 4 GB to be a fair starting point for a standard configuration. You might get away with less if you’re using legacy applications, but remember that all the new System administration stuff is still in Java.
  • Remember to buy a Console. The HMC is the best technical solution, but far too expensive. You can got with OpsCon (requires a PC) or with the Thin Console (a special Neoware appliance).
  • The low end model only includes 3 months of software maintenance, and does not include CRU (Customer replaceable unit) service. Make sure that you have SWMA as long as you’re using the machine (it’s a support contract and a license upgrade contract). The CRU service is also important if you do not have on-site IT staff.

If you fix all these things, remember that you’ll probably increase your system price by about 50%-75% – but that’s just the way this game works. It exactly the same in the System x world, or even when you’re buying a car – all upgrades add extra cost.


  1. Beware: The pitfalls of the System i 515 — The iSeries blog:

    [...] Beeler has a post on his blog about the things to keep in mind when considering buying the System i 515. When IBM rolled out the i5 515 Express and i5 525 Express in April, most of the talk was around [...]

  2. Ann Richmond:

    That is why (regetably) we have moved all our development off the iSeries and onto stand alone linux servers. The iSeries still serves the data, but the application runs on the Linux server which is MUCH faster and MUCH cheaper and just as reliable. For data intensive apps, we have to move the data off the iSeries because it can’t handle the load without a major upgrade. The iSeries is no longer a cost effective business solution and neither is Microsoft. IBM has abandoned the small business market and selling low cost ineffective solutions just does not cut it. Linux and open source are the way to go.
    Thanks. Ann

  3. Lukas Beeler:

    Ann, i don’t fully agree with you on the Microsoft part. Mostly because Windows Server is the best way to manage Windows Clients. And as it is now, it’s very difficult to replace Windows on the Desktop – especially in the small Business segment, where Microsoft offers _very_ competitive pricing with it’s Small Business Server Product (which i don’t like that much, but the pricing is good).

  4. Ken Glazer:

    i515 Express is a powerful system that comes in three configurations , not one as implied. Dual core 64 bit processor running a 1.9GHz clock will get the job done. If you need more add a second dual core processor. Yes you will want more memory and the same for disk. The i515 holds 8 x 70GB drives which is usually enough for a small business. Keeping in mind that you can logically partition this system into servers that run Hosted Linux and i5/OS (for your production and development partitions) at the same time. The i515 has announced support for MYSQL and PHP if you want web applications. Bottom line this is a very strong solution for small business, especially where uptime is important and technical staff is small. The i515 can run with just a system operator. And if a problem occurs, the i5/OS has help text and error messages that tell you something about your problem and suggest possible ways to fix the error. The system is called System i, because it is a fully integrated solution.

    For a console the thin client is the lowest cost device you can get. I would not think that many i515s would have need for an HMC. An HMC would only be required if you had over 4 logical partitions.

    The real limitation on the machine at announcement was the 40 user limit under i5/OS. That has now been removed. You acquire user licenses for a one time fee of $1,250 for 5 users. Maybe not as cheap as MS CALs but the i5/OS users are concurrent. Once you sign on you can have multiple sessions without need for additional CALs.

    And if you have need for multiple windows or linux servers, you might want to consider using the i515′s IFS as a SAN where your server image and data reside. Or just use it for file and print serving.

    If you want a system that will sit in the corner and no one ever know that it is there, the i515 is a top performer.

  5. Lukas Beeler:

    Ken: You sound more like a marketing guy than a technician ;)

  6. Chris Hird:


    I have just purchased a new i515 with the very base configuration possible. I will only be using it for test and development of the products we produce so it does not have to be a performance monster. But for what it cost in comparison with previous models we have used (170,270,520) the performance is very acceptable for what we need. I will be setting this up as a LAMPS server which we will publish on our blog to show how easy it is to set up and run. The performance numbers will only start to show once we get some activity going but first impressions are its going to be be very acceptable. If I had taken IBM’s suggested config I would have 4 disks, 4GB memory, Raid 5, and a full software stack. We don’t need that and managed to get the cost down from $24,000 to just over $6,000 with our discounts, $18,000 saved is what impressed me! I already have a 520 which I use for development and that cost me over $16,000 and it ‘appears’ to be just as quick?

    I commend IBM for at least putting something in the market which has a very keen price point, its not for replacing servers such as 520′s and some of newer technology, but I would match it against a lot of the old 600 and 700 series out there and at a cost which could be lower than your maintenance cost for those systems!


  7. Lukas Beeler:


    The base configuration can be perfectly suitable for one or two users. And of course the performance is a lot better than a 170, 270, or a castrated 520. The 170/270 are over five years old, that’s a lot of time if we’re talking about IT products, and the 500/600 CPW 520/520+ were slow to begin with.

    I don’t compare the 515 to it’s predecessors, i compare it to what else you can get on the market for that money. And this is where the System i looks very bad – for 15’000 CHF i can get a baseline machine thats rather slow, can’t do LPARs, etc. pp. For 15’000 CHF, i can get a very powerful Linux/Windows server with a full 8 disk package, lots of RAM, etc.

    Have you ever upgraded a 520 with 600 CPW and 2 disks from V5R3 to V5R4? Takes about 30 hours. Not an acceptable timeframe, at least in my opinion. It shows that the machine is underpowered for the OS it runs, and i5/OS is very demanding when it comes to the hardware.

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