Are there 'CPU Only' computers?



  • I feel like there are 'CPU only'* computers, computers that have no hard drives, that their sole purpose is to receive commands from a master server and do computations and return the results of said request - the computer has no ability to store the data beyond possibly using a HDD as raw swap if it doesn't fit in ram or whatever...

    But I can't find anything on google, and the concept intrigues me. Has anybody heard of computers like this? Am I just dreaming shit up that has no practical purpose? Is it only used in the highest conspiratorial tech at google, and they are hiding the results to preserve their IP?

    . * No OS is installed, bare bones, raw metal computations using the processor only.

    Why am I asking? No particular reason actually, I was just pondering over the practicality of such a build and possible uses, and wanted to see if anything like that actually existed.


  • BINNED

    Something like Nvidia Tesla?

    I'm sure there are more, but Tesla popped up in my mind immediately.


  • SockDev

    The nearly-dumb terminal returns.



  • That's pretty much the concept, but that's a graphics card processor, not a typical CPU processor. This is really good for high numbers of fast computations, but doesn't work as well in long running environments. (Though the Tesla is still heavy duty)

    Think just raw slave computer that the master farms out computational work to, and returns. It is to @Arantor's point, is true dumb. (Not a terminal, but dumb server...? I don't even know what you'd call it, which is part of the problem with my google fu)

    [Or maybe more accurately, to develop on the tesla, you need to use nvidia's proprietary language, it can't use something like compiled .net code to my knowledge.]

    [This line of thought is mostly because I'm just interested in raw computational power theories since I tend to work with big data. It's fun for me to think about.]



  • Persistent memory is too cheap I guess.

    You'd always need some code to connect to the server and receive data anyways, since it's far from trivial.



  • I'm guessing the extremely tiny market for these is adequately covered by the fact that you can build your own with little cost/effort.



  • @anonymous234 said:

    You'd always need some code to connect to the server and receive data anyways, since it's far from trivial.

    I was assuming netboot. You could also boot off a cheap USB memory stick, I guess, but then you have storage so the "purity!" of the solution is gone.



  • Well, you could always boot from usb and load the "operating system" in to ram and remove the usb.

    That still qualifies, I think. (ramdisk gogo?) [Netboot is more what I had in mind though]



  • @Matches said:

    Well, you could always boot from usb and load the "operating system" in to ram and remove the usb.

    That still qualifies, I think. (ramdisk gogo?) [Netboot is more what I had in mind though]


    There used to be, and I bet they are still there, Thin Clients that had no HD only an internal flash card for OS, drivers, cache and persistent stuff. So I see literally no point why you would plug a usb stick in and then remove it.


  • BINNED

    @Luhmann said:

    There used to be, and I bet they are still there, Thin Clients that had no HD only an internal flash card for OS, drivers, cache and persistent stuff.

    Thought of that first (as in, even before the Tesla) but I considered them to be a bit more complex than what Matches had in mind. Then again, I was buttuming, and we all know how that usually ends.



  • @Onyx said:

    Thought of that first (as in, even before the Tesla) but I considered them to be a bit more complex than what Matches had in mind. Then again, I was buttuming, and we all know how that usually ends.

    I think he's more going in the direction that google, facekoob, and others are taking with their hardware design. A server is just a box containing 'processing' or 'storage' unites. The processing unites are really just that: a cpu, memory and interconnects.
    See http://arstechnica.com/information-technology/2013/02/who-needs-hp-and-dell-facebook-now-designs-all-its-own-servers/



  • By the time you're paying for fiber interconnects all over your data center, you might as well put some small SSD in the damned thing while you're at it. If only for caching.

    EDIT: well I guess that makes no sense because you could just double the RAM. But point is: fiber shit is expensive, and really limits how you can built-out the data center. I'm guessing Facebook probably plans-out on the level of entire racks, or possibly even entire rooms, not just on the level of "let's add a new machine here".



  • When I read this, I thought of stuff like DSPs or specialty encryption hardware or even something like an EPROM.



  • The 'put a usb in then remove it' was being a bit flippant. If I was going to use a usb, you might as well put in a cheap small ssd that does the same thing. (and at that point, you pretty much may as well go the full OS route, even if it's just a lightweight linux OS)

    Quote from that facebook article

    It could be as simple as the plastic bezel on a server with a brand logo, because that extra bit of material forces the fans to work harder. Frankovsky said a study showed a standard 1U-sized OEM server "used 28 watts of fan power to pull air through the impedance caused by that plastic bezel," whereas the equivalent Open Compute server used just three watts for that purpose.

    The fact that they are looking at it like this is, IMO, pretty fucking cool. At a small scale, it doesn't matter, but once you start really revving up things like that would add up fairly quickly. (I doubt I would ever get anywhere remotely the size of what facebook is concerned with, but I like to dream big about my own EDW store for the analytics platform I'm working on.)


  • BINNED

    @Matches said:

    The 'put a usb in then remove it' was being a bit flippant. If I was going to use a usb, you might as well put in a cheap small ssd that does the same thing. (and at that point, you pretty much may as well go the full OS route, even if it's just a lightweight linux OS)

    I pretty much have an old HP thin client doing exactly that. It has 1GB of flash memory installed, and it currently houses a as-small-as-we-could-get-it install of ArchLinux with X and LXDE running on it. Used as a presentation machine pretty much, since cramming a full PC in the space it occupies proved a bit... difficult.

    Note that we still had to use btrfs with compression enabled if we wanted to run any kind of desktop environment on it. But for CLI-only install, 1GB of flash is perfectly adequate.


    Filed under: Unless you forget to map /tmp to RAM...



  • @Matches said:

    If I was going to use a usb, you might as well put in a cheap small ssd that does the same thing.

    The USB is a lot cheaper, since you don't really care about speed in this context.

    You buy one $5 USB memory stick, shove your crap on there, and live the rest of your life free from worrying about configuring the netboot crap correctly or ever having to plug in a monitor to see the BIOS screen.

    Sure you could use a SSD for the same thing, but then you're paying at least $50 for the same benefit.



  • Go more meta, use a card reader so you don't have the ugly stick 😃

    But what I'm getting from this discussion, is there are some things that are 'kind of sort of similar' in concept, but overall it doesn't really exist.

    There's something like this though, which is in that direction.

    [Yes, I know these have been around for a while.]


  • Grade A Premium Asshole

    That is just a server motherboard? Unless I am missing something.

    The closest I can think of in concept would be a virtual host, booting from USB and using a SAN for storage.



  • Yes, it's a server motherboard. But after you've added four processors it's basically a 'cpu only' machine.

    It's not really what I was talking about originally, but the end result is more or less the same.



  • I did this before using a Knoppix boot CD, hehe



  • greenarrays' multiprocessor forth chips might fit the description, I guess.



  • @tufty said:

    greenarrays

    Well fuck, no wonder I couldn't find much literature.

    On a side note, paste image from clipboard works in discourse. Pleasantly surprised.



  • Intel's Xeon Phi (and its predecessors) might fit the bill. It's essentially a PCIe card with a bunch of Intel CPUs and some RAM. It's mainly targeting HPC applications (it's somewhat similar to NVIDIA's Tesla stuff). It's marketed as a coprocessor, so it should work as mentioned in the original question -- i.e., the host sends tasks to the card, which processes these and then returns the results. Not sure about the details, haven't had the chance to play around with one of them.


  • :belt_onion:

    @Matches said:

    On a side note, paste image from clipboard works in discourse. Pleasantly surprised.

    Only in certain browsers.



  • @Onyx said:

    Used as a presentation machine pretty much, since cramming a full PC in the space it occupies proved a bit... difficult.

    Have a look at Intel's NUCs. They're tiny, pretty cheap, and you can put any size SSD in them.
    @blakeyrat said:
    You buy one $5 USB memory stick, shove your crap on there, and live the rest of your life free from worrying about configuring the netboot crap correctly or ever having to plug in a monitor to see the BIOS screen.
    Netboot is pretty simple to set up, and depending on BIOS might actually be faster than booting off USB.



  • @ender said:

    Netboot is pretty simple to set up, and depending on BIOS might actually be faster than booting off USB.

    Maybe but you still need to dig around the back of the rack to plug a monitor in, or use a rack with a monitor shelf and KVM, and that's an annoying time-sink PITA and/or a waste of space.



  • Hey, they're unprecedented...

    they're actually really fucking cool, but a total buttfuck to program.



  • @blakeyrat said:

    Maybe but you still need to dig around the back of the rack to plug a monitor in, or use a rack with a monitor shelf and KVM, and that's an annoying time-sink PITA and/or a waste of space.

    Huh? Every machine I've seen so far boots off network by default if it doesn't find any other bootable device (as long as PXE ROM is enabled, and except on laptops, they usually are).



  • All I can say is you ain't buying machines from where I be buying machines. I've never seen PXE boot turned on by default.


  • Grade A Premium Asshole

    @blakeyrat said:

    I've never seen PXE boot turned on by default.

    The Dell and HP servers that I have purchased over the years have had PXE boot on when we took them out of the box and anytime you reset the BIOS to defaults.



  • @Intercourse said:

    The Dell and HP servers that I have purchased over the years have had PXE boot on when we took them out of the box and anytime you reset the BIOS to defaults.

    Well I should mention I haven't bought a server, or been in charge of server-buying, since about 2004.


  • SockDev

    @blakeyrat said:

    Well I should mention I haven't bought a server, or been in charge of server-buying, since about 2004.

    So your knowledge is nicely relevant to how things are today?



  • Open the time pod door, HAL.



  • As long as we're on the topic of servers, is there such a thing as an 'ultra quiet' server [that isn't complete shit]? The 2950 I bought sounds like a fighter jet during boot, and is still quite noisy during normal operations (though I'll admit, I was expecting that)

    For long term, I'd prefer something beefier, but more importantly, quieter as it will be used in a somewhat small room / shared office space - no server closet. (the longer term hardware for this project will have a higher budget)



  • @Matches said:

    As long as we're on the topic of servers, is there such a thing as an 'ultra quiet' server [that isn't complete shit]?

    Yes, but only on the condition you don't put it in rack-mount hardware. There's no way to make a rack-mount server quiet.

    Shove it in a tower case with some nice quiet 120mm fans, or if it's not too beefy just use a Shuttle or Desktop form-factor.



  • Sort of what I was afraid of. I guess that's not the end of the world.


  • Grade A Premium Asshole

    @blakeyrat said:

    Yes, but only on the condition you don't put it in rack-mount hardware. There's no way to make a rack-mount server quiet.

    As with most things, speaking in absolutes is usually wrong.

    Of the same generation, the Dell 2900 rackmount server is pretty quiet. It is a 4U or 5U form factor, and is also available in a tower configuration and once it is booted, it makes roughly the same amount of noise as a desktop PC. Really, what makes servers so loud is the fan size and the cramped quarters of 1U and 2U boxes. Once you go to the larger form factors, they are pretty quiet due to being able to fit large fans that can move large volumes of air without having to resort to high RPMs.



  • That's what I'd heard - but the 4U and 5U servers are likely out of my price range in the short-medium term, but I'd be interested in seeing some possibilities.

    The alternative would be to get a beefy motherboard with something like 4 sockets, and slap in 4x whatever the high end socket is when the time comes, tied with some SSD for caching/serving pages. Should handle the medium-early long term quite nicely.


  • Grade A Premium Asshole

    They are not that cost prohibitive. As you mentioned, the other option is to build it yourself and do so in a 4U or 5U rackmount case. That comes with several significant drawbacks though. You massively reduce your ratio of processing power to rack space. In a home/dev environment it is not that big of a deal. In a datacenter, it makes a huge difference in cost.

    You also lose a lot of OOB LOM possibilities, which also only matters once you move to the datacenter. I have yet to see a home-rolled or whitebox server that has any significant OOB LOM capabilities. Once you are managing more than a few servers, I think it becomes essential.



  • OOB LOM? Out of band, lights off management (google implies)?

    That's also not that bad, and if I scaled up from my prototype, that would be in my price range.


  • Grade A Premium Asshole

    Correct. Think Dell's DRAC combined with OpenManage.


  • Discourse touched me in a no-no place

    @Arantor said:

    So your knowledge is nicely relevant to how things are today?

    Expressing opinions on things you know nothing about is a time-honored tradition. People have been doing it for hundreds, if not thousands, of years.


  • SockDev

    @antiquarian said:

    Expressing opinions on things you know nothing about is a time-honored tradition. People have been doing it for hundreds, if not thousands, of years.

    I forgot, this was humanity we were talking about.



  • @Arantor said:

    I forgot, this was humanity we were talking about.

    I thought we were talking about @blakeyrat.



  • @Matches said:

    I feel like there are 'CPU only'* computers, computers that have no hard drives

    IIRC, we used something like that as a printer spooler in the late 90s. Just some old mainboard without a hard disk, booting a customized linux from floppy and doing nothing apart from printer spooling.


  • Grade A Premium Asshole

    Come to think of it, some of the old Beowulf clusters would mostly fit the bill also. I CBA to find the article, but I remember someone making one out of Mini-ITX (Via-era) that booted from PXE and kept the minimal OS in memory with no hard drive. The nodes were just motherboards with RAM on them.



  • @blakeyrat said:

    Well I should mention I haven't bought a server, or been in charge of server-buying, since about 2004.

    They did that around 2004 too. Lost a lot of time booting those because DVD/USB boot was behind PXE.

    @blakeyrat said:

    Yes, but only on the condition you don't put it in rack-mount hardware. There's no way to make a rack-mount server quiet.

    It's not the rack-mounting but the small/thin form factor that makes the noise go up. Used a lot of 4-5u servers in the day and they where acceptable on the noise level. Not like a tower model but definitively not deafening like a 1u server. Had one of those under my desk. Made a great place to put my feet up and recline.
    On the manufactures pages look under 'tower servers' and not rack servers. A lot (not all) of the servers can be turned into rack models as well.

    @Matches said:

    out of my price range

    I think that depends more on the other requirements of the server then the form factor.



  • @antiquarian said:

    People have been doing it for hundreds, if not thousands, of years.

    People have probably been doing it since they gained the language complexity required to discuss non-immediate things.



  • @Matches said:

    I feel like there are 'CPU only' computers, computers that have no hard drives
    Why has nobody mentioned embedded systems yet? Has that meme died out?



  • Because embedded systems aren't CPU only computers?


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