EPP and how it works

[scotland21]

Can someone explain how EPP works and if you have to set the memory manualy with EPP timings??

[Baddriver]

Hi

I haven't scrupulously check my source material but reckon this should be 99% accurate.

EPP was a joint standard first developed by nVidia and Corsair to do with memory. Historically, memory comes with a little E2PROM device onboard which can be read by a motherboard chipset to see what speed a memory device should operate at and what latencies to use (JEDEC standard settings).

I think EPP stands for enhanced performance profile and for a system to automatically use it, you'll need a motherboard that supports it (nForce 4 or 5 chipset) and some recent memory that also supports it (e.g. Corsair XMS2). As well as JEDEC settings, the memory chip also contains this enhanced profile and the motherboard will recognise this and change speed and latency (and possibly command rate and voltage) to match. Note that EPP settings are not an overclock as such (or at least not a marginal or unstable bodge) but rather guaranteed to work by the manufacturer at optimal settings.

If you have EPP memory then fire up CPU-Z and you'll be able to see both the JEDEC and EPP values. This method can be used to manually set-up a system without supporting motherboard by writing down the values and setting these manually in BIOS.

Does this help?
Stuart

[scotland21]

Cheers Stuart for the information.
I have the Abit AN9 32X Fatality board and I have purchased some EPP corsair memory due to some issues with my OCZ memory and I found the system doesn't automatically change the memory settings to the EPP timings.
I have changed the voltage and timings myself but I would like to confirm if the bios of the motherboard should change the timings or is it meant to be changed by the end user??

[Baddriver]

The AN9 does use an EPP enabled chipset so it should be able to use these settings. I'm afraid I haven't used one before so a way to check is to download the latest version of CPU-Z (http://www.cpuid.com/cpuz.php) and flick to the memory tab. If the settings you're running at now don't match what you're expecting the (the EPP settings can be seen on the SPD tab) then it hasn't worked.

Stuart

[scotland21]

Sean, can you confirm if EPP memory should be changed to EPP timings automatically by the bios of the ANp 32X fatality.