Ask Dan: What motherboard for a Core 2 Duo E4300?

Date: 23 February 2007
Last modified 03-Dec-2011.


Would the Intel Core 2 Duo E4300 CPU work with a ASRock 775i65G-R2 MicroATX LGA775 motherboard?

Aus PC Market's listing for this CPU says "i975/965 boards recommended". What does that mean? Will this chip work with any i865 boards?


The reason why 975 or 965 chipset motherboards are recommended for the new(ish) "Conroe" core Intel CPUs is, in a nutshell, that older boards aren't likely to have the VRM (Voltage Regulator Module) version 11 specification power supplies needed to run the new chips.

But, of course, it's more complicated than that.

For a start, the E4300, like the other 4000-series Core 2 Duos, is widely alleged to not actually have a Conroe core. It is, instead, supposed to be "Allendale", which is like Conroe only with 2Mb of level 2 cache instead of 4Mb.

Except it isn't. As with budget versions of other core designs, the E4x00 CPUs are just the same thing with half of the cache disabled (possibly because some of it failed tests, possibly just for artificial market-segmentation reasons). And, as with many "sawn-off" CPUs, the E4x00s also have a lower bus speed - 800MHz stock speed, instead of 1066MHz.

This, of course, means that running a 4-series Core 2 Duo on a 1066MHz-capable motherboard is an open invitation to try overclocking it that far, and beyond.

Anyway, whatever the reason, the lower-cache, lower-speed chips should use less power (at stock speed...) than the higher-cache ones.

Now, the version 2 ASRock 775i65G, which you have, is alleged to support Conroe processors. And I dare say it does, and should have particularly little difficulty feeding the lower power models. There's nothing stopping any LGA775 board from supporting Conroe as long as the BIOS recognises the new CPUs in some vaguely adequate way, and the power subsystem is adequate.

But Conroes are, nonetheless, still not actually on the 775i65G's list of supported CPUs. That's probably because ASRock haven't bothered updating the list since the v1.0 775i65G came out. But still, on your own head be it if the thing turns out to reboot every 20 seconds.

(A reader's now pointed out to me that there's a separate CPU support list for v2.0 of the board, with plenty of Conroes on it. So that's all right, then.)

The 865 chipset is certainly hanging in there. It's more than four years old now, which is positively ancient for a consumer desktop chipset - though early motherboards that used it are completely incompatible with all new CPUs, on account of having the old Socket 478 rather than LGA775.

Here's a jumping-off point for information on overclocking-friendly Core 2 Duo motherboards.

(Because, as everybody knows, it's against the law to buy an E4300 and then not overclock it - see bus-speed reference above.)

Shoppers from Australia and New Zealand can buy the highly overclockable Core 2 Duo E4300 from Aus PC Market.
Click here to order!