Epox 8RDA3I my story so far

I have an Athlon XP-M 2500+ batch AXMH2500FQQ4C on a Epox 8RDA3I mobo with NVIDIA nForce2 Ultra 400 chipset. I have 1GB of DDR (2x512 MB) of Kingston PC3200 KVR400X64C3 and an XFX GeFORCE FX 5700 Ultra 128 MB DDR3. I use air cooling on the processor with a Vantec Aeroflow VA4-C7040.

I managed to overclock the processor to 2430 Mhz (180x13.5) which gives 2441 Mhz actual clock rate. I did two mods on the socket: An L12 mod to get the maximum FSB speed and a higher multiplier mod to get multipliers above 12.5. The voltage is VCore = 1.750V, VDimm=2.90V and VDD=1.6V.

I was not able to increase my FSB to 200 Mhz and beyond. I noticed that the L12 mod was necessary to raise the FSB beyond 170 Mhz but even after the mod the memory could not handle more than 185 Mhz FSB. I am very sure it is the memory problem because I was able to run the system at 210 Mhz with no problem when I had the memory run asyncrously with an FSB divider. I am sure it is not a processor problem as I had the processor clocked up to 2.5 Ghz without any problems.

The serial on the memory chips is W942508CH-5 which I think is made by Winbond and it is PC3200 memory. I have two stiks placed on dimm 1 and 3 to utilize the 128-bit mode that the nForce 2 supports. I called kingston next and asked them about that issue and they told me that the recomended memory for all EP-8RDA3 is 333 Mhz memory. I insisted and they told me that 400 Mhz memory is unstable on these mobos and they are not recomended.

Next I contacted Epox. I told them about my problem and they told to try memory latencied 7-3-3-2.5. Those latencies made the system more stable but it still cannot pass a thorough Prime95 test. When you lower the FSB down to 185 Mhz then the system becomes stable.

Then next thing I did was to place memory coolers to cover the memory sticks. That didn't help much. Later I noticed that the shoubridge gets really hot. Much hotter than the northbridge. So I ordered a Vantec Iceberq CCB-A1C and placed it over the northbridge. I moved the original heatsink over the southbridge and I placed a fan over the southbridge heat sink.

The temperatures while running Prime95 are 54C from the processor and 42C for the chipset but I am having the side panel of the case removed (I assume the temperatures will go higher once I close the case). After wasting many many hours of testing with Prime95 and Microsof memory diagnostic I was not able to make the system stable at 200 Mhz FSB.

Currently the status is (200x12.5) 2500 Mhz and very frustrated. Anybody run into similar problems? Any help or suggestions is appreciated.

Welcome to the Forums!

First off CH-5 is a Winbond chip, I have them on my Buffalo PC3200, they will run ~210FSB in dual-channel & 220FSB in single channel @11-3-3-2.5 on Auto VDimm. What Buffalo does & I suspect Kingston as well is to OC them at the factory as CH-5 is technically a PC2700 memory chip. What I discovered was that set to Auto for VDimm its actually running ~2.74V which is the factory OC. The CH-5 also has a built in regulator that kicks in ~2.8V & exceeding this can cause instabilty. Unless you have a board like the DFI Infinity Ultra or a volt mod which can supply over 3.0V VDimm at which point the onboard regulator stops workings you won't acheive anything using 2.9V VDimm & could be causing issues, try setting to Auto VDimm with the 11-3-3-2.5 timings. I also discovered that by switching to single channel w/ my sticks in slots 1 & 2 I could acheive 10FSB higher stable in Memtest & Prime. My benchmark tests showed that by running 5FSB higher I could equal the performance of dual channel in all tests & surpass them in some, you might try this experiment yourself sometime.

Many of the Mobiles don't seem to like running over 200FSB so thats another possible issue. Try what I mentioned with your RAM & see if you can run higher, otherwise you should be able to get 200FSB stable using a 12.5 multi. Remember that your board, CPU & RAM take some time to burn in to reach there peak performance level, this can take some time depending on how much you use it. I ran Memtest all night & Prime all day the first few weeks to get mine all warmed up.

Keep an eye on those temps as you may need to improve your case & CPU cooling as you push higher. Are you using MBM5 or Speedfan to monitor your systems voltages, temps & fan speeds?

Good Luck!

Regards, Balrog

Thanks for the fast response. I tried those settings and even though it made the system a bit more stable it still would not pass the Prime95 torture test.

Its funny cause now I am running the same test @190 Mhz and it has been running fine for half an hour now. Just 10 stinky Mhz will not let me run the memory in its supposed potential. Is 10 extra Mhz a big deal? Probably not but it is a matter of principle and I am not going to rest till I get there.

Well I decided, unless I have other sugestions, to keep those memory settings and run Prime95 for at least 3 hours every day raising the FSB by one each day till I hit 200. In ten days I should be there.

Thats the spirit!!!

Sometimes ya gotta teach em whos boss!!!

Did you try single channel or just the 11-3-3-2.5 timings?

Your RAM should run 200FSB at defaults as thats what its sold as but I wouldn't RMA it personally as Winbond stopped making memory & CH-5 sticks with ~3.2V VDimm have been known to run ~250FSB in sync so even if your current board doesn't offer that much the next might.

Yeah, keep pushing it with Prime & Memtest & it'll come around, make sure if your BIOS has it to disable C1 Disconnect & Thermal Throttling.

Good Luck!

Regards, Balrog

I would rather run the system in dual mode memory. After all thats the reason to get an NF2 mobo.

Any more help is welcome. The 8RDAI is the same mobo as the 8RDA3+ only without the firewire and the dual lan. So any recomendation for the 8RDA3+ also aply for the 8RDA3I.

It has been more than 10 days now. I started at 190 FSB which was really stable after several hours of Prime95. When I tried 191 FSB it failed after some time. I tried to run as much as I could Prime95 to burn in the board and memory. Currently I stopped at 195 Mhz. I have been trying memory latencies 11-3-3-2.5 and 7-3-3.2.5 with no big difference really.

My system is stable in all Windows applications but cannot run Prime95 more than 30 min. Let me know if you have any ideas of things I can do to improve the FSB. Note that the problem is with memory.

UNBELIEVABLE: As I was getting frustrated about my 8RDA3I I decided to follow Barlog's recomendation and try setting the memory in non-dual mode. Those who have motherboards of the series EP-8RA3 know that there are 3 banks. Bank 1 has its own bus while banks 2 and 3 share a common bus.

I had my memory dims placed in bank 1 and bank 2 to enable 128 bit transfer through dual bus. Before I put the dims in banks 2 and 3 for plain 64 bit mode I tried banks 1 and 3. Well the stability issue was magically solved. I run now my system at 210x12 or 2520 Mhz and tested with Prime95.

So for those who have memory and stability problems with EP-8RA3 mobos at dual memory mode you can try switching the dims between banks 1,2 and 1,3 to see which one allows the highest increase to the FSB speed. If that fails too as a last resort dish the dual mode and try banks 2,3.

In single channel mode above 200FSB about 5FSB increase in bus speed will equal dual channel performance at the lower speed. i.e. 205 single channel is about the same as 200 dual.