Kingy said:
Surely though if the board is stable running a E6300 at stock 266FSB without PCI lock issues, then you could run a E4300 at that same 266FSB and there'd be no issues?
OK - Every CPU has an identifier in the BIOS and some microcodes associated with it that tell the BIOS what to set itself to.
E4300 - 9x Multi, 200MHz FSB, 33MHz PCI, 100MHz PCIe
E6300 - 7x Multi, 266MHz FSB, 33MHz PCI, 100MHz PCIe
So when you increase the FSB by 1 on the E6300 you go to;
E6300 - 7x Multi, 267MHz FSB, 34MHz PCI, 101MHz PCIe
Increase it by 34 and you have;
E6300 - 7x Multi, 300MHz FSB, 67MHz PCI, 134MHz PCIe and the computer fails to boot. because the graphics, SATA, PATA, memory controller are all so massively overclocked they just fall over. Basically no PCI lock, carp overclocking.
The same goes for the E4300 - overclock it by 34 FSB and what do you get?
E4300 - 9x Multi, 234MHz FSB, 67MHz PCI, 134MHz PCIe and it falls over.
Hence you can't overclock without a PCI lock and a PCIe lock.
The ASUS P5L-VM 1394 has a PCIe lock, but no PCI lock so you can overclock a bit harder, but not much (350FSB with an E6300).
Kingy said:
Does the PCI based instability occur if the PCI slots are unused?
I'm afraid so as the SATA and PATA interfaces take their timings from the PCI and PCIe clocks, as does the graphics card (obviously) and the network card (less obviously).
Kingy said:
I understand that things are only as strong as the weakest link, but if both chip and board will run at 300FSB separately, then why can't they do it together?
See above - you have an uncontrolled overclock in a major system timer and it just falls over.
Kingy said:
If the E4300 would only clock to 225FSB with the Asrock Conroe945G-DVI, the there's no point in me getting that chip, I might just as well pay the extra tenner and get a E6300 and have the VT support and faster native FSBs
I think the difference is significantly less than that at some stores - some places have them £3 different at the moment. And yes, I would advise you to look at the E6300 as a better long-term bet as the E4300's are proving to be a bit hit and miss as overclockers.