ECC/registered memory slower than non-ECC/registered memory?

[Chumster]

Just curious if there was any sort of performance hit when using ECC and/or registered memory. Thanks.

Chum

 

[SCSIRAID]

There are slight performance degradations associated with either ECC or registered memory.

ECC penalty is associated with read/modify/write cycles when a write addresses less than the full memory width (8 bytes). No penalty if you write the entire 8 bytes.

Registered memory requires an extra clock on the first access to account for the address register loading.

 

[boyRacer]

There's about a 2% hit on performance... it's minimal yes... but considering how people overclock and squeeze out even the most minute performance out of everything... that 2% might mean a lot.

 

[SCSIRAID]

Agreed... There are benefits that you are trading for the performance degradation. ECC checks and correct single bit memory failure which to me at least is valuable. Registered memory allows for a large number of DIMMS or for DIMMS with multistacked chips or sides. That is far less value to me. One mans benefit is another mans slow piece of crap

 

[AndyHui]

Please read the FAQ: What is ECC SDRAM? Should I buy this over normal SDRAM?

Fully re-written and updated.

 

[LAUST]

But isn't the payoff of that 2% where ECC is maybe more stable? Not tossing in bits of bad data?

 

[boyRacer]

This is off crucial.com regarding ECC vs Non-parity memory:

"If you are building a PC and deciding which type to use, the following guidelines should help. If you plan to use your system as a server or a similar mission critical type machine, it is to your advantage to use ECC. If you plan to use your PC for regular home, office, or gaming applications, you are better off with non-parity.

ECC (error correcting code) memory performs "double bit detection and single bit correction." This means that if you have a single bit memory error, the chipset and memory will find and repair the error on the fly without you knowing that it happened. If you have a double bit memory error, it will detect and report it. Using ECC decreases your PC's performance by about 2%. Current technology DRAM is very stable and memory errors are rare, so unless you have a need for ECC, you are better served with non-parity SDRAM."

Hope this helps.