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Difference between ECC and Non Parity

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What is the difference between the ECC and Non Parity ram. Is one faster than the other? thanks in advance
 
I think non-parity is the same as non-ECC. I think ECC leads to better stability but an argument could be made that it's slower. (I couldn't make the argument, it just seems like i've heard that somewhere.) I'm really no expert on this, anyone know for sure?
 
ECC means: the Error Correction Code, when there is an error in the ECC memory it will try too correct the Error so that your computer won't crash!!

No-parity memory won't be checked for errors, soo the BIOS can't see if this memory is damaged!
 
What RedHairedHat wrote is not entirely true.

Here is a somewhat simplified explanation:
ECC (Error Checking and Correction or Error Correction Code, I've seen both) memory checks for errors and attempts to correct them on the fly.
It can correct most single-bit errors and some multi-bit errors without crashing or rebooting the system. If it can't correct the error it reboots the system with the bad memory mapped out so it will not be used.

The BIOS checks ALL memory (ECC, Non-ECC, Parity, and Non-Parity alike) when the system attempts to boot. That's what the memory count, on boot up, does. If it finds bad memory it will not allow the system to boot.

Parity memory also checks for errors on the fly but doesn't make corrections.

Good quality, modern memory has very few errors. That's why most modern systems don't use ECC or Parity memory. That's also why the memory test on boot is reduced to one iteration (Allow Quick Boot setting in BIOS), to speed up the boot process.

ECC is useful for servers or systems running "mission-critical applications" which can't afford disruptions.
ECC memory is not needed for most "home use or small office" computers; if the memory is bad, replace it. Good quality memory has a lifetime warranty.

ECC memory will not fix General Protection Faults, Invalid Page Faults or other errors which are caused by software.

Some chipsets, especially older ones, do not support ECC. So, check the motherboard manual before buying ECC memory.
ECC memory is more expensive and is also slower due to the error checking overhead.

If you feel you need ECC memory and your system supports it, remember that ECC and non-ECC memory, usually, can not be mixed. If it is mixed the ECC capabilities, usually, do not function.

Just thought I should clear that up.

Hope this helps. Good luck.

John
 
John's exactly right. ECC memory is ideal for servers or environments where you are trying to minimize the number of reboots required to keep a system or network stable. For basic home and business pc's, you do not need this more expensive memory.

Just to confirm what John touched on, you can never mix ECC and non-ECC memory. If it is mixed, your system will not boot or will hang.
 
Also not true.
The fastest EDO memory has a speed of 50ns with a burst rate of 5-2-2-2 at 66MHz. Which is 11 clock cycles per burst.
The slowest SDRAM (PC-66), since the 430TX chipset, has a speed of about 15ns with a burst rate of 5-1-1-1 at 66MHz. Which is 8 clock cycles per burst.
Even with the increased overhead associated with SDRAM, the slowest SDRAM memory is about 20% faster than the fastest EDO memory.

John
 
I think RedHairedHat must have it confused. EDO memory succeeded standard DRAM. You typically found EDO RAM on mobos that supported the earlier pentium and pentium-pro procs. Then came SDRAM at 66Mhz and was typically found with the P-II and AMD K6-II. After PC100 SDRAM was released, DDR RAM and RAMBUS RDRAM soon followed.

EDO is definitely a technology of the past and utilized the outdated DRAM technology.
 
When you're talking about ECC and non-ECC memory, you're talking about error correction or "parity". This has hardly anything to do with burst rates or the memory "speed".

The advantage of parity memory is that it has the ability to correct minor errors that would normally lead to BSOD in a normal environment.
 
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