ECC?

[jormar23]

I was looking at either video cards or harddrives I don't know which. just curious what is ecc. on some things it say ecc and on others it say non-ecc just curious which one is better

thanks'

chris

[Scoobz]

Stands for Error Checking and Correcting.

My understanding is that it will check all data being read and written and correct it (on the fly) when required.
Different from parity in that parity only checks and doesn't correct.
ECC would be the logical choice but i assume there is a price to pay?!?? on the flip side there must be a "lag" in data transfer compared to non ECC products or am i completely wrong??


Scoobz

[Scoobz]

Hey, just noticed i've made member status!!

Yipeee!!!!

[Cody]

Uh... ECC is much slower than Non-ECC... so if you are doing memory-speed-requiring-programs (games, visual stuff) I wouldn't reccommend it

[Bovon]

DRAM has an ECC (Parity) type as well as registered type. Both cause a slight delay in processing data due to the extra clock cycles needed.

I presume it was some class of RAM you were looking at.

Most motherboards used in home type computers use unbuffered non parity (ECC) and non registered SDRAM (Synchronous DRAM).

Video cards use several types of ram. Included are:

SDRAM,

Short for Synchronous DRAM, a new type of DRAM that can run at much higher clock speeds than conventional memory. SDRAM actually synchronizes itself with the CPU's bus and is capable of running at 133 MHz, about three times faster than conventional FPM RAM, and about twice as fast EDO DRAM and BEDO DRAM. SDRAM is replacing EDO DRAM in many newer computers

Today's fastest Pentium systems use CPU buses running at 100 MHz, so SDRAM can keep up with them, though barely. Future PCs, however, are expected to have CPU buses running at 200 MHz or faster. SDRAM is not expected to support these high speeds which is why new memory technologies, such as RDRAM and SLDRAM, are being developed.


SGRAM,

Abbreviation of Synchronous Graphic Random Access Memory, a type of DRAM used increasingly on video adapters and graphics accelerators. Like SDRAM, SGRAM can synchronize itself with the CPU bus clock up to speeds of 100 MHz. In addition, SGRAM uses several other techniques, such as masked writes and block writes, to increase bandwidth for graphics-intensive functions.

Unlike VRAM and WRAM, SGRAM is single-ported. However, it can open two memory pages at once, which simulates the dual-port nature of other video RAM technologies.


WRAM,

Short for Windows RAM, a type of RAM developed by Samsung Electronics that supports two ports. This enables a video adapter to fetch the contents of memory for display at the same time that new bytes are being pumped into memory. This results in much faster display than is possible with conventional single-port RAM.

WRAM is similar to VRAM, but achieves even faster performance at less cost because it supports addressing of large blocks (windows) of video memory.

VRAM,

Short for video RAM, and pronounced vee-ram. VRAM is special-purpose memory used by video adapters. Unlike conventional RAM, VRAM can be accessed by two different devices simultaneously. This enables the RAMDAC to access the VRAM for screen updates at the same time that the video processor provides new data. VRAM yields better graphics performance but is more expensive than normal RAM.

A special type of VRAM, called Windows RAM (WRAM), yields even better performance than conventional VRAM.

DDR

The more recent type ov video card ram is DDR. It is generally faster that the other types, and is now being used on the better video gaming cards.

[This message has been edited by Bovon (edited 08-30-2001).]

[JimJr]

Bovon thanks for all the information. This is what makes this forum what it is and why I read it every day.
Jim

[BBA]

Uh... ECC is much slower than Non-ECC... so if you are doing memory-speed-requiring-programs (games, visual stuff) I wouldn't reccommend it


Not really. It is actually a smaller difference than setting latency CL3 from CL2.

The difference in speed is NOT noticeable over normal deviation in measurements AND the increased stability makes a HUGE difference if you don't like blue screens and rebooting very often.

[The Clank]

Check out: http://www.corsairmicro.com/main/tecc.html

[Bovon]

Thanks, Clank. That was good reading, and very informative. I have been to Corsair's web site many times, reading up on ram tecnology but missed this one.