Asus M4A88T-M barebones kit unstable on OS install

tecnotron
06-02-2011, 11:26 PM
http://www.techspot.com/news/33610-amd-phenom-ii-am3-do...

By Jose Vilches, TechSpot.com
Published: February 13, 2009, 6:03 PM EST

Barely a week after the introduction of new Phenom II processors for the AM3 socket, reports are beginning to emerge about an alleged bug within the DDR3 memory sub-system. Specifically, a revision guide document for the processor mentions that on machines with more than one DDR3-1333 (or greater) memory modules installed per channel, users may experience “unreliable operation.”

Without getting into the specifics of the symptoms, AMD’s Damon Muzny has acknowledged this issue, and also took the time to clarify the situation. According to him, internal testing showed that with certain lower quality memory modules and all four slots populated (2 modules per channel), inter-component signaling could become erratic and result in system instability. Muzny says they were faced with a choice: to either drop listing support for DDR3-1333 altogether or design the system to down clock the memory to 1066 – they took the most conservative approach and went with the latter to ensure stability.

He went on to suggest how users could manually configure memory to compensate for the slight drop in performance and assured customers that the issue is of a software nature and that it will be fixed shortly.
tecnotron
06-02-2011, 11:30 PM
http://tech.icrontic.com/news/amd-explains-phenom-ii-me...


Damon Muzny, a PR representative at AMD, took the time to explain the situation. Yes, the Phenom II doesn’t “officially” support four sticks of DDR3-1333 or DDR2-1066. Internal testing showed that four sticks triggered instability in multiple test platforms when using standard JEDEC voltages and speeds. Two high-speed sticks on a single channel can push the memory controller’s limits; combine that with subtle variations in motherboard architectures, and inter-component signaling can become erratic.

“We had to make a choice,” Muzny said. “It was enough of a problem that we had to make a choice.”

Overclockers know that a bump in voltage is the easiest way to fix memory instability. A little extra juice in the system keeps things working correctly and will allow users to fill all four memory slots on their motherboards.

According to Muzny, AMD had three options for rectifying the Phenom II’s memory situation:

No official support of DDR3-1333 and DDR2-1066 in any capacities.
Require motherboards to run outside of JEDEC voltage specifications when they detect two memory sticks on a single channel.
Clock memory down to fail-safe speeds.

Muzny said not supporting DDR3-1333 and DDR2-1066 would be a terrible choice because both speeds work, and requiring motherboards to run out of official specifications still left room for instability or legal troubles. Downclocking was the safest bet catering to the lowest common denominator and, as such, motherboard manufacturers were instructed to have the BIOS downclock DDR3-1333 to DDR3-1066 and DDR2-1066 to DDR2-800 to ensure stability.

“We have to take the most conservative approach,” Muzny said.

Overclockers and enthusiasts are still encouraged to manually set memory parameters for stable operation. After all, the most popular overclocking RAM already runs well outside specification. In the end, it’s nothing new. It’s just AMD playing things safe.

According to Muzny, future chip revisions could address the issue, but the problems aren’t just caused by the Phenom II’s memory controller. Motherboard manufacturers will need to use quality components to ensure clean, clear signals if they want to do their part.