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How Many Desktop PCs Can One Server Replace?

NZheretic asks: "HP has just announced that they have upgraded a four-processor server with Advanced Micro Devices' new dual-core Opteron. The amount of processing power a multi-processor multi-core system can deliver seem like a waste of processing power for most traditional servers, which are more likely to suffer from disk access bottlenecks before lack of processing power becomes a problem. But what if that power could be delivered direct to the desktop users? The HP ProLiant DL585 supports eight 64-bit PCI-X I/O Slots (Six 100MHz, two 133MHz). The ATI FireMV(TM) 2400 supports Quad DVI/VGA displays on PCI Express. Assuming that you leave one PCI-X slot for a multiport USB card, thats up to twenty eight displays with USB keyboards,mice and headsets that could theoretically replace twenty eight networked desktop PCs. Using DVI and USB extenders, not all of the user stations would have to be within the 7.5 meter cable distance imposed by the DVI cable limit. The only OS currently capable of supporting this many displays is Linux. What limits would be imposed by the hardware and PCI-X bottlenecks? Taking into account the added cost of the HP and ATI hardware, could it deliver a great reduction in the total cost of ownership over both traditional PCs and thin client systems? How many desktops is it practical for a high end server to directly replace?"

13 of 107 comments (clear)

  1. PCI-X != PCI-Express by anderm7 · · Score: 4, Informative

    Pci-Express and PCI-X are not interchangable. PCI-X is really fast PCI, where-as PCI-Express is different altogether (Although a PCIe to PCI/PCI-X bridge is supported).

    Depending on how these systems are configured, it may not be possible to use that many monitors.

  2. WAY too expensive. by FreeLinux · · Score: 3, Informative

    OK. Given that a two processor version of the DL 585 is $16,000US and does not include any storage, we can assume that a fully loaded box processors, memory and some storage, is going to run $28,000 plus and that doesn't include monitors. That's more than $1,000 per user just for hardware. Since the average business PC runs under $1,000 the server solution that you suggest just isn't cost effective.

    Now add to that cost, the single point of failure issue. Even if the hardware never fails, all you need is for some malicious or clueless user to run :(){ :&:;};: at a bash prompt and you're fired.

    1. Re:WAY too expensive. by Omega+Hacker · · Score: 2, Informative

      Also, the person asking the question doesn't seem to understand the difference between PCI-X and PCI Express. PCI-X is just a faster/wider version of normal parallel PCI, while PCI Express is a serialized version. Those cards will not work in that server, or *any* server I've seen.

      That said, I have personally done the multi-seat thing, with the appropriate X patches (built into Ubuntu's x.org, had to patch Debian's xfree86) and the right hardware. I'm going to be deploying quad-seat machines to a small town in Bolivia. But it's not the simplest thing to do (yet), and I had no luck with Userful's software. Maybe now that I have more homogenous hardware it might work better.

      --
      GStreamer - The only way to stream!
  3. PCI-X by bartjan · · Score: 3, Informative
    This is a server, and it does not have any PCI Express slots. Those shiny ATI cards won't fit. I believe Matrox has some cards that support quad head on PCI.

    Why do you need an USB card? The server already comes with 2 USB ports, and an USB bus supports up to 127 devices.

  4. Addendum by FreeLinux · · Score: 2, Informative

    I forgot to metion that the same super server could service hundreds of concurrent users if you used Linux or Citrix with thin clients. Depending on your applications disk io is not the big bottleneck. Usually when it comes to terminal server bottlenecks it is memory, processors, and then disk io.

    When you do it this way, the cost goes down in dramatic fashion. A $50,000 server setup is only $250 per user when you have 200 users running off it and A server as large as you suggest could easily run 500 or more users concurrently, which would further bring the cost down to $100 per user!

  5. workstations - none, servers - quite a few by gtrubetskoy · · Score: 4, Informative

    How many desktops is it practical for a high end server to directly replace?

    None, just like a big truck doesn't replace any passanger cars.

    You could, however try something like OpenVPS to replace a couple 'o dosen servers with it...

  6. Repeat after me PCI-X != PCI Express by eht · · Score: 2, Informative

    No one makes PCI-X display adapters, only regular PCI ones, and those are getting harder to find and unsuitable for what you desire.

    This machine has 0 AGP and 0 PCI Express slots, only "Graphics Integrated 1280 x 1024, 16M color on PCI local bus, 8 MB of SDRAM video memory".

    Neat idea, but sorry.

  7. PCI-X != PCI-Express by photon317 · · Score: 3, Informative


    PCI-X is not PCI-Express, and the two technologies don't even have compatible pinouts or signals. PCI-X is the follow-on to traditional parallel PCI, with speeds of 100 and 133 Mhz and a 64-bit wide data path (compared to previous parallel PCI standards of 32/64-bits at 33/66 Mhz). PCI-Express is PCI re-done serially instead of in parallel, in an attepmt to be fashionable like the new Serial ATA standard. It's also potentially faster than PCI-X, and not at all compatible.

    You'll notice just about every communications standard that doesn't go long haul alternates back and forth between parallel and serial methods every few years just to sound new and exciting and better.

    --
    11*43+456^2
  8. I hate to flog Windows, but.. by Myself · · Score: 4, Informative

    There's a product called Buddy that's been doing this for many years. Originally, the Buddy card was a combined PCI video card and PS/2 keyboard+mouse controller, which spit all the signals out an 8-position modular jack (RJ45 for the cretins), and a little breakout box at the other end of a (long, shielded cat-5) cable accepted the monitor and input devices. The software gave two Windows95 users the impression that they were the only one on the machine, and I'm still not sure how they did that on a non-NT architecture, but it worked and worked well. Only trouble is, the video bandwidth of the cable was limited, and the RAMDAC in the video card didn't support sync rates over 60Hz, so the flicker on the slave station was pretty obnoxious.

    In the years since Buddy was first released, PCI video cards have learned to play nice with their neighbors, and USB has provided a way to connect oodles of keyboards and mice to the same machine. Thus, Buddy is reincarnated as BeTwin, a software-only product that associates specific keyboards, mice, and video cards with specific sessions on the machine. (I'm not sure how it deals with sound. Multiple soundcards would seem easy.)

    They say it only supports 5 users, but that sounds like an arbitrary limit and I'm sure they'd tweak a 28-user version if you felt like it.

    Related links... I'm going off-topic here, but playing stupid tricks with virtual hardware is fun.

    Check out MaxiVista, a "virtual video card" which Windows treats as a second monitor, allowing you to do multi-head tricks. The data for the second display goes out over the network (a la VNC) to a client machine, which simply pipes it into the video buffer. Turn that scrap laptop into a second monitor! I stuffed a 10base-T card in my old lappy and it was perfectly usable for everything except fullscreen video. At 100 or gigabit, it'd be worth a try.

    Xinerama is Linux software that does the same thing, creating one large virtual X display, which then chops up the image and sends it to a number of smaller actual displays, some or all of which can obviously be located across the network.

    As long as we're doing silly tricks with virtual hardware, you should be aware of Virtual Audio Cable, which enables digitally-perfect audio patching between applications' outputs and inputs, even if the apps themselves think they have exclusive control over the soundcard. (Also enables multiclient sound output under 9x, even if your card doesn't support it, because it does software mixing.)

    If video is your thing, try Softcam, to feed your videoconferencing software any old source you feel like. Switch between actual cameras, use your desktop screenshot as a "camera input", add effects, etc. Their WaveMux tool is a nice complement to VAC, too.

  9. How Many Desktop PCs Can One Server Replace by Anonymous Coward · · Score: 1, Informative

    Huh? It depends on the application. You could run 1000 dumb terminals in a call center with a single 900 MHz P3 based machine. Old Sun SPARC 2 can handle 64 dumb terminals without breaking a sweat.

  10. Re:SunRay + V480 by SunFan · · Score: 2, Informative


    For the "but the V480/V490 can't be ordered for $999 from Dell" trolls, there's also the v40z Opteron server that now sells with 4 dual-core CPUs.

    However, for supporting a 100 desktops, something as robust as the V490 might be a good thing.

    --
    -- Microsoft is the most expensive commodity operating system and office suite vendor in the marketplace.
  11. Re:Linux is no good by homer_ca · · Score: 4, Informative

    It'll work with Linux, but you need a patched kernel. See here.

  12. Re:SunRay + V480 by SunFan · · Score: 2, Informative

    people will soon see that Sun is a bargain.

    Sun is definitely a bargain, now, but they have to overcome the baggage of having the UltraSPARC II stuck at 480MHz while the UltraSPARC III was being delayed. That is the source of most of the "but my Pentium is five times faster for 1/20 the cost" trolls. Fortunately, that is _not_ a problem, anymore.

    --
    -- Microsoft is the most expensive commodity operating system and office suite vendor in the marketplace.