Defective memory on my 7970?

[ddd1]

I have a watercooled 7970 with wery good temperature on Core and VRM.

If I run low speed on core I can downclock the memory to 1060mhz.

However there comes I point, where if I overclock the Core enough I have to keep memory at stock speed 1375mhz.
Right now I'm running it at 1275core/1375memory, the highest temperature is on VRM and it's 72c so I'm still not having temperature problems...

However having memory at 1375mhz I'm sure the card will degrade faster and use 10-25w more power

I try MSI AB and when I put unofficial overclocking to 2, then all the fields in MSI AB are empty beside Vcore.
So I use MSI AB for overvolting and cgminer for overclocking, 1243mv, 1275/1375 cgminer.

[muqali]

I haven't been on the forums long, but isn't there a consensus that memory generally can't go too much below the core clock? Not in absolute MHz but too far out of a certain ratio and it gives issues. My guess would be the careful timing, buffers and whatever other hoodoo they do to get GDDR5 working at 5500MHz.