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What's the difference between server-grade RAM and desktop-grade RAM?

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Quality (i.e. reliability), error correction and often the ability to have them replaced when they start warning of failure rather than after failing.

  • 3
    +1. Don't forget price! – gWaldo Nov 21 '10 at 14:37
  • Where your point about ECC is correct, the rest is debatable and subjective. Most server and desktop DIMMS are made in the same factories, using the same components by the same machines. – Paul-K Oct 4 '17 at 20:32
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    SEVEN YEARS ago this was more accurate. – Chopper3 Oct 4 '17 at 20:42
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Server ram can be error correcting (ECC) or non-ECC. With the current quality of RAM, ECC is losing ground. The other difference is Registered/buffered RAM. This allows servers to access more ram due to the lower electrical load on the memory controller. Many servers require registered memory but some of the newer servers don't, but even the newer ones can handle more RAM if registered memory is used. Both ECC and registered memory are more expensive than desktop memory.

Hardware is cheap; downtime is expensive.

  • That has nothing to do with SERVER ram. I have workstations running on ECC ram. ECC is a technical ability. You can get ECC ram for servers and workstations. – TomTom Nov 21 '10 at 17:55
  • ECC is primarily useful for detecting/correcting errors that are caused by the environment (gamma rays, etc...) or supporting circuitry (power supply, or timing issues). – JGurtz Nov 22 '10 at 18:17
  • @TomTom - The motherboard must support ECC or you're just waisting money. That isn't to say that some Workstations may be ECC capable. However the vast majority of Desktop PCs do not suport ECC RAM. @JGurtz - Agree 100%. – murisonc Nov 22 '10 at 19:51
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What's the difference between server-grade RAM and desktop-grade RAM ?

Quality. The rest is not an issue of "server to workstation" but specific technical requirements (ECC, registered etc.) that is well documented.

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Like the others said, but I will expand:

  • ECC -- Most "SERVER" dimms have an extra DRAM per rank to enable ECC. This is also known as "check bit"

BUFFERED vs UNBUFFERED

  • RDIMM -- Some server DIMMS will have a BUFFER or REGISTER chip designed to re-broadcast the CA (command/address) signals to all the DRAMS on the DIMM. This reduces load on the CA bus, but has the negative effect of slowing everything down by 1 D-clock (think cas latency here, you will get a +1 on all timings)

  • LRDIMM and FBDIMM -- All signals are buffered and thus these dimms are typically very expensive.

  • DRAM width -- Most desktop products (CPU's) only support x8 and x16 DRAMS where servers will support X4.

  • Number of slots -- Servers often support more slots per channel than desktop (hence the need for BUFFERED dimms)

0

Its like

[NONECC] vs [ECC - { minus 2 / 3% speed } ]

[PHP NTS] vs [PHP TS - { minus 5 / 10% speed } ]

  • Actually it is not. Most my workstations run on ECC ram (DDR2 ECC), none of my servers would accept that - they require registered (which includes ECC but is more). This is like saying racing engines are racing engines because tehy don't run on diesel. – TomTom Nov 21 '10 at 17:56
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    Registered and ECC have nothing to do with each other. It is technically possible to have registered non-ECC ram. But, because most machines that require ECC ram for error correction also require registered RAM (to allow more slots) you won't find it – JGurtz Nov 22 '10 at 18:13
  • Agree again with JGurtz. Also, many of the newer servers can run unbuffered (non-registered) RAM; just not as much. – murisonc Nov 22 '10 at 19:55

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