Well Overclockers came before me here... ;-). According to various forums ViaHardware #1, ViaHardware #2 and AMDMB forums and by self experience from yesterday it seems highly likely that the KR7A-R has memory timing issues that result from the fourth DIMM slot on the board. Read more...
Abit had similar issues with their BH6 motherboard and it was generally concluded that there were interference patterns (multipath signals) which resulted in memory problems. This was more apparent with multiple RAM modules. This "fix" was to locate RAM modules in certain DIMM slots which, it was thought, cancelled out these "reflection errors" - it worked for many BH6 users. Overclockers.com now has done some extended testing on the memory stability of the KR7A-R and in some cases the board failed and once even refused to boot. I was confronted with a similiar issue yesterday after I had to switch a DDR2100 module from DIMM slot 1 to slot 3 (now populated slots 2+3 with 256MB each). Before - when slot 1 and 2 were used - I could use the most agressive RAM timings CL2.5 - Trp:2 - Tras: 5 - Trcd:2 - DRAM Command Rate: 1T and all was well. After the DIMM switch I got LOADS of BSOD's in Windows to a state where it became unusable like from 10 seconds to every ten minutes a crash... I had to revert back to default settings and was looking for a solution. I came across the forums mentioned above and some users suggested upping the FSB to 136-138Mhz. Finally 138Mhz FSB did the trick for me and except DRAM Command Rate set to 2T now (still does not work) timings are back to initial settings and the board is now stable. This leads to the impression though that we are indeed talking about signal interference. Interesting about this is that Overclockers found no problems when using DIMM slot 2 and 3 at 133Mhz FSB while my board malfunctioned! I will test a 512MB Corsair memory stick soon and see if it makes a difference compared to two 256MB sticks... Please post your comments! Also note the article poll we are running!
Abit had similar issues with their BH6 motherboard and it was generally concluded that there were interference patterns (multipath signals) which resulted in memory problems. This was more apparent with multiple RAM modules. This "fix" was to locate RAM modules in certain DIMM slots which, it was thought, cancelled out these "reflection errors" - it worked for many BH6 users. Overclockers.com now has done some extended testing on the memory stability of the KR7A-R and in some cases the board failed and once even refused to boot. I was confronted with a similiar issue yesterday after I had to switch a DDR2100 module from DIMM slot 1 to slot 3 (now populated slots 2+3 with 256MB each). Before - when slot 1 and 2 were used - I could use the most agressive RAM timings CL2.5 - Trp:2 - Tras: 5 - Trcd:2 - DRAM Command Rate: 1T and all was well. After the DIMM switch I got LOADS of BSOD's in Windows to a state where it became unusable like from 10 seconds to every ten minutes a crash... I had to revert back to default settings and was looking for a solution. I came across the forums mentioned above and some users suggested upping the FSB to 136-138Mhz. Finally 138Mhz FSB did the trick for me and except DRAM Command Rate set to 2T now (still does not work) timings are back to initial settings and the board is now stable. This leads to the impression though that we are indeed talking about signal interference. Interesting about this is that Overclockers found no problems when using DIMM slot 2 and 3 at 133Mhz FSB while my board malfunctioned! I will test a 512MB Corsair memory stick soon and see if it makes a difference compared to two 256MB sticks... Please post your comments! Also note the article poll we are running!
