Which CPU

  • Trying to decide between some different CPU's for a 2.0 build.

    Choices are ; Core2 Duo P8400 2.26GHz/1066MHz/3MB/2Cores/25W

    Celeron M T3100 1.90GHz/ 800MHz/1MB/2Cores/35W CPU

    T7500 2.20GHz / 800MHz / 4MB / 2 Cores / 35W CPU

    Intel Celeron M 550 2.00GHz/533MHz/1MB/1Core/31Wat

    This will be for a Pf 2.0 build running FW/Router/Squid - SquidGuard - LightSquid/Snort/Ntop/FreeSwitch + possibly free radius

    Planning on at least 4Gb of RAM, possibly 8Gb if needed.

    Given what i want to run will there be any great difference between the CPU's listed?


  • What bandwidth are you planning on using this with? With Squid and Snort I'd suggest a dual core processor, just to avoid a badly tuned Snort install causing you problems. However if you're looking at under 50 Mb/s or you know how to properly tune Snort it probably won't matter.

  • Bandwidth will be a blazing 1M/bit Down and 1M/bit UP - its all we've got and can get here. About 20 users will be behind the FW.

    So what your saying is that from that list of CPU's it wont make a difference as long as i stick to a dual core? Will a Dual Core Celeron be able to keep up with the load? Further, does this imply that a high end mobile CPU is essentially wasted on a PF setup? I guess if one wanted to run PF in a VM the high end CPU's come into their own. However i am not so sure running PF in a VM is the way to go - getting off topic now however…...

    So i can save a ton of cash by going for a Celeron dual core over a Core2 Duo. I wonder how much difference there will be between a 2.6Ghz Core2 Duo and a 2.0Ghz Dual core Celeron?

    Looking on Ebay i see heaps of second hand Core 2 Duo CPU's - do CPU's wear out ? If not a second hand CPU on a new motherboard could be the way to go?

    Thanks for your input Havoc

  • There is wear and tear on CPUs from normal usage but even then, the CPU will probably last 2 to 3 times what your intended lifespan for it will be.  Easily decades for the lifespan in usage (no overclocking or overvolting).

    A dual-core Celeron will suffice but you should note that Celerons do not support EIST (Speedstep) so the operating power consumption may actually be higher than the Core 2 Duos.
    You might want to grab the mobile Pentium Dual-core series instead.  e.g.  T3200 or T3400.  These are basically the same as the Socket P Celeron Ms but will have EIST support.  A T3400 would be about US$30 with free shipping in the States on ebay.

  • Thanks dreamslacker

    How would any of the so far mentioned CPU's compare to the Atom D525?

    I just want to make sure i build an appliance with enough horsepower to run the packages i mentioned earlier. Also is 3Gb of RAM enough for Squid/SquidGurard/LightSquid - Snort - and Ntop ?Is it a case of the more RAM the better..IE would 4 Gb or even 8Gb or Ram enable the packages to perform better? Is 8Gb of Ram over the top for the packages mentioned and if so how do we size up Ram requirements for packages? I want to make sure i add enough but dont want to waste money putting in Ram that will have no real world effect.


  • Socket P CPU's are easily found. It's the motherboard that's harder to find. Plus new socket P mobo's are selling high.

  • At 1Mbit/s every single one of those is overkill.  I'd suggest something along the lines of an Atom.

  • Its not the 1 Mbit/s that is the problem - its the Squid/Snort/Ntop + whoever knows what package comes down the pike later on that we may need.

    From Comments so far it seems a low end Core 2 Duo is plenty enough. Common sense tells me that 4Gig Ram should be well enough but as i said earlier i wonder if 8G RAM boosts performance significantly or is there a point of diminishing returns ? Ram seems to be cheap at the moment - at least compared to what i was looking at this time last year when i was wanting to put a late model workstation together.

  • Without the 64bit install anything over 4 GB is likely to be wasted.

    Even then, you don't need a powerful CPU to run Snort on a 2 Mb/s link. You'd have to load up just about every VRT and Emerging Threats rule and set out to badly tune Snort to have any chance of heavily loading any of those. Squid doesn't eat that much CPU either, mostly just RAM. I've certainly run Snort (well tuned) plus Squid and other packages on a 1 GHz system with 1 GB of RAM and no problems.

  • OK then thats it then - low cost ore 2 DUO CPU will do the job at hand with room to spare. Thats great because Ebay is full of them for not much money. Seems to be a good way to get a powerful appliance - Socket P board with 4 X Intel 82574 G/bit NICs on board + low cost used Core 2 DUO CPU. The socket P board is pricey but when combined with the low end second hand CPU the cost is very reasonable and it will handle all the packages i want to run.

    Is there any reason to not run the 64 bit version of PF ? Or is it wiser to stick to 32 bit for now?

    Is there anything obvious I'm missing here? I want to put together a number of these.

    appreciate the input.

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