Well, a bit of info about those PQI sticks on P4C800-E:
Those are PQI PowerMemory 1GB Sticks (aka MD441GUOE - no heatspreaders). I used DRAM voltage of 2.85v, since at lower voltages the RAM didn't always want to startup at all, when overclocked.
In single channel I could get one stick of four to pass MemTest at 225MHz 3-3-3-6, I didn't try to load Windows and check the stability, since Single Channel isn't an option for me.
At 230MHz both 3-3-3-6 and 3-4-4-8 gave me errors at the 98%-99% of Test #5 - about 600 errors.
The 2nd and the 3rd sticks failed the Test #5 the same way the 1st stick did, but at 225Mhz, and passed at 220MHz. :slap:
The last stick didn't want to OC around 220MHz at all, the system got stuck on the POST screen, so I didn't test it anymore :stick:.
The strange thing is, three sticks of four fail at the 2-3 last percents of the Test #5 (they don't fail the tests #1-#4, but I didn't go further than #5, probably they fail some following tests too, I really have no much time for this), what is that? What could be the reason of systematic failure at the end of the Test #5? :confused: They don't overheat - that's for sure.
Ok, that's not all, there're 4 more sticks left in the store, I'm going now to exchange the 3 lazy sticks for the new ones, and maybe I'll be lucky to find another stick that will do 225MHz, since I don't need more: 282MHz / 5 * 4 = 225.6MHz.
Another strange fact is, in Dual Channel the sticks don't like the 2:3 divider - 282MHz / 3 * 2 = 188MHz - underclocking actually - but the sticks didn't pass the Test #5 this way... :nono: Why? :confused:
Still, the pairs of 1st + 2nd or 1st + 3rd sticks are SuperPI stable at the 250MHz with the 5:4 divider (DDR400) and 3-3-3-6.
By the way, Crucial's Z503 didn't start at 282MHz neither with 5:4 divider, nor with 3:2.
But a pair of Kingston HyperX PC3200 256MB (BH-5 - my 1st RAM) worked perfectly 2-2-2-5 with any divider at any frequency around 200MHz.
What do you say, guys, anything you can advise? Thanks anyway for reading all this.
Lood007 - thanks, man :).