PCTuning fórum

Krteq píše:Tak pokud mikrokód není úplně stejný, tak už z principu věci není úplně stejný i čip (ASIC) - i když je změna minimální, tak tam prostě je

Blue Storm píše:Ty spíš řekni, jaký rozdíl je v tom, že to jádro je na 100 % stejné nebo na 95 % stejné. Pořád je to víceméně to staré přeznačené jádro s párem optimalizací.

Krteq píše:Tak pokud mikrokód není úplně stejný, tak už z principu věci není úplně stejný i čip (ASIC) - i když je změna minimální, tak tam prostě je

There is no physical difference between project 215-08520xx ("Hawaii") and 215-08800xx ("Grenada") ASICs.

The only difference between the full variants (i.e. 44 CUs and 64 ROPs) is binning and fuse configuration.

215-0852000 - Hawaii XT (67B0h DID, MA-RID 0h, MI-RID 0h)
215-0852022 - Hawaii XT(L) (67B9h DID, MA-RID 0h, MI-RID 0h)
215-0880004 - Grenada XT (67B0h DID, MA-RID 8h, MI-RID 0h)

The XT(L) bin is the highest quality of Hawaii family ASICs.
The dies are binned for lowest possible leakage characteristics in order to reduce the power consumption and dissipated heat. It is only used in 295X2 cards.

"Grenada XT" has the highest leakage characteristics of Hawaii family.
Higher leakage makes it possible reach higher clocks without violating the design electrical characteristics of the die, in terms of voltage. The down sides in using high leakage ASICs are the higher temperatures through the board and higher power consumption (due temperatures and lower VRM efficiency).

Any performance difference between "Hawaii" and "Grenada" cards is caused by the display driver. AMD changed the fused configuration in a way the driver can tell the difference between "the old" Hawaii and "the new" Grenada cards. They both obviously share the DeviceID but "Grenada" cards have their revision number bumped to 8h (instead of 0h on Hawaii). The revision number is configured by the fuse configuration during manufacturing and cannot be altered by the bios on retail cards.

If you are testing differences between "Hawaii" and "Grenada" bioses, note that "Grenada" bioses have higher clocks thru the different performance states than "Hawaii" bioses. This means that if at some point the card reaches it´s power limit and starts to shuffle through the different performance states, the "Grenada" cards might appear to be faster than "Hawaii" simply because of the higher clocks. If you are testing the differences between the two bioses, make sure you have the power limit set to the maximum setting (+50%) on both of them.

ps. Internally "Grenada" has been called as "Hawaii Refresh".

If you know how much there actually is difference in previous "refreshes" by AMD, then it is futile to argue if "Grenada" is the same ASIC or not

Krteq píše:Zdroj?

//Našel jsem - Guru3D forums - The Radeon R9 390 and 390X Aren’t Rebadges

Tohle ti tam můžu během deseti minut postnout taky

The point being made is that on the line between a straight up re-brand and either a new chip design or a die shrink, what AMD is doing this time around is closer to a re-brand.

Same chip, same node, but more mature version of the 28mm fabrication process.The silicon process has been changed. Apparently they are not the same chips pulled out of a big box of Hawaii chips. They are an improved stepping or perhaps a new process ? Who knows ? Anyway, that's the official answer.

It will sell for the same price as the older version soon, so no panties need to be put in a bunch over this. Just right now priced a bit higher to help clear out old stock.

RAD-x píše:... a pořád to stojí stejně za ho.no? To není moc dobrá vizitka...