Quick search provides that no firmware update or software enabler for these is necessary?
(Would’ve been my first question.) Seems odd if it does not require such measures.
Did you try “bumping” the CUDA?
Any time a change of this sort is undertaken, seems that a general “self accounting”
by the machine would be necessary? No specific instructions provided with the upgrade?
Might try a desktop rebuild or PRAM zap to see if any difference might then be noted…
before trying the CUDA. Anyone have firsthand experience with this particular upgrade?
AND were there two different versions of these…
one for Quicksilvers and the other for earlier machines?
And ya can always turn off that memory test.
Check and/or replace thermal paste.