if you are running just a water block then no a cold plate really isn't all that necessary, but if you use a peltier, then yes a cold plate is really necessary...
a cold plate help not only to transfer the cold more effeciently but also it stabilizes the temps from the coldplate to the cpu much much better then just a peltier... while a peltier can suffer some fluctuations in its thermal output, the coldplate can really be benificial in helping to keep those temps stable...
now as to material: i would recommend silver if you can get it... otherwise copper will be your best bet... 1/4" to 3/8" thick is good too...
ronx (Jan 12, 2001 05:26 p.m.):
hi all
Is it necesarry to use a coldplate with the peltier ? why can't it be mounted direcly on the cpu die ?
thankz for reply's