GTX 4xx series and GDDR5 EDC memory checking

I know that only the Tesla Fermi range has full ECC checking. (i.e. both external and internal memory and buses)

Do the GTX 4xx series (including the GTX 460) perform GDDR5 EDC memory checking and retry as per the ATI 5870?

The Fermi architecture white paper says it does.

The Fermi architecture white paper says it does.

It says the architecture supports it, not that the GTX 4xx cards have it enabled.

We know that the Tesla has all of the ECC features enabled and that the GTX 4xx series don’t.

The question is did they also disable EDC retries for the GTX 4xx series.

From http://www.elpida.com/pdfs/E1600E10.pdf


The GDDR5 SGRAM calculates the CRC checksum on-the-fly for each Read or Write burst and returns the checksum to the

controller on the dedicated EDC pin. The controller performs the same CRC calculation; if both checksums don’t match a

transmission error is assumed and the controller is supposed to repeat the command in error.


It says the architecture supports it, not that the GTX 4xx cards have it enabled.

We know that the Tesla has all of the ECC features enabled and that the GTX 4xx series don’t.

The question is did they also disable EDC retries for the GTX 4xx series.

From http://www.elpida.com/pdfs/E1600E10.pdf


The GDDR5 SGRAM calculates the CRC checksum on-the-fly for each Read or Write burst and returns the checksum to the

controller on the dedicated EDC pin. The controller performs the same CRC calculation; if both checksums don’t match a

transmission error is assumed and the controller is supposed to repeat the command in error.