Twinmos PC3200 not doing so well. Comments please

[markrb]

I bought 2 256MB PC3200 Twinmos modules to put in my Epox 8RDA+
and I am rather dissapointed with the results. I have requested an exchange
already.
With my 2200+ CPU set at 9X I cannot even POST at 200Mhz.
At 175Mhz I have to use rather relaxed timings and at
180Mhz I have to use the slowest timings.

I am setting the CPU multiplyer really low on purpose just to test the memory.

Could it be something else causing these issues or is it most likely the RAM?

Thanks,
Mark

 

[jpetermann]

If it can't do its rated speed, definately return it. i just got my 2 sticks and all seems to be well. I am running on a p4g8x though, so I am nowhere near rated speed.

PJ

 

[wicktron]

Your inability to hit 200MHz can be attributed to a lack of VDD voltage. This is a common problem among users of the 8RDA+ as documented at the Xtremesystems and AOA forums.

 

[drewski]

to test the memory run your FSB & memory async. i.e. FSB = 166 Memory = 200 (i.e. 120%) or an even bigger separation in timing.

 

[Bartman39]

I agree to seperate your memory and run it at %120 or more with lower clocked speed on your cpu... That should test the memory... Also the memory is rated for CL 2.5 not CL 2.0 @ 400 DDR speed... But most have had good luck with very fast timings... Also what voltage are you running the memory at...? I have mine at 2.77 (2.70 actual) and can run 2-2-2-6 @215fsb (430 DDR)... Yes I have the Twinmos\Twinmos cheaper stuff...

 

[LastRide]

use one stick in the dimm closest to the CPU and crank it.Overclocking with 2 sticks on the 8RDA+ could be a pain.This will tell you how good your sticks are.Try one at a time and 3:4 or 4:5 ratio

 

[human2k]

Originally posted by: wixt0r
Your inability to hit 200MHz can be attributed to a lack of VDD voltage. This is a common problem among users of the 8RDA+ as documented at the Xtremesystems and AOA forums.

wut he said.

 

[markrb]

Bartman39 are you running sync or async?

If I put the system to 170 FSB / 205 Memory it seems to work, but my Sandra scores drop like a stone.

I wonder if it really is running at 205. If it is it seems stable. I haven't run Prime95 for more then a minute, but
it doesn't crash right away like sync mode did.

I also have the newest Bios. I have heard some say that it doesn't work as well. I will flash it with the 1/29 version and see what is up.

I will also pull 1 module and see what I can do. Part of the reason I went with this board was the 128 Bit memory, but if it reduces the speed
then it isn't worth it.

Any links to these posts about the VDD problem? I don't know those sites mentioned.

It's just that I have read of way too many success stories with default voltage and sync mode.
Most are at 6-3-2-2.

How can I be sure the memory is really running at 205Mhz? Sandra just says I am at 170Mhz which is my fsb speed.

Thanks,
Mark

 

[Bartman39]

Markrb... Yes mine are in sync... the idea of pulling 1 to test with is good also you might have one stick that is not quite up to par...? Also I am running the 1/29 bios and since my system is stable and no problems I`ll stay with it till I hear better things on the newer ones...

 

[markrb]

Update. I lowered my PSU voltage to a steady 5.05V. It was running about 5.23V which was needed
for my old board.

I installed only 1 stick and pumped it until Prime95 failed using 2.77V and 100%.
I placed the stick in slot 2.

Stick #1 did 190Mhz and stick 2 did 189Mhz MAX. 1Mhz at this speed is really little difference.

I am going to place stick 2 in slot 3 to keep it at 64 Bit and see if 128 bit was what was slowing me down those
few Mhz. Also I was able to use slightly tighter timings of 6-3-2-2.5.

I would still like opinions on whether I should RMA the board and try to get a better one.

Mark

 

[Bartman39]

markrb

Take a look at your southbridge and what are the last digits in the line of numbers...? A2 or A3...?


If its A2 then go here


Sorry I had said northbridge but meant southbridge...

 

[markrb]

Is there anyway of telling without removing the heatsink.
I don't want to chance not being able to return it if I decide to.

Would Sandra or MBM5 tell me what version?

Thanks,
Mark

 

[drewdogg808]

Originally posted by: markrb
Is there anyway of telling without removing the heatsink.
I don't want to chance not being able to return it if I decide to.

Would Sandra or MBM5 tell me what version?

Thanks,
Mark

no, the only way is to take the heatsink off. sandra reports it incorrectly.

 

[AJF01]

Don't put too much faith into the stepping thing (A2/A3). Some people even say that rev1.0 of 8RDA is a better overclocker than rev1.1. This A2 vs A3 is all speculation and theories that hasn't been proven. I'm not saying is not true, however it is all speculation at this time.

markrb,
Do you happend to have memtest86? if not, please download and use it to test the memory one stick at a time.

In addition, it has been documented many times that it is not easy to run above 200mhz SYNC on the 8RDA+ without mods. The 8RDA is rated @ DDR333, and running DDR400 is a big Overclock for this board. That's why the famous vdd mod. In addition, getting A3 stepping is not a guarantee 200Mhz FSB SYNC. And having A3 stepping on the SB doesn't guarantee A3 on the NB, one must remove the HSF in order to determine NB stepping.

That's why I agree with others here, that in order to to test the memory (the mobo is another issue) you need to run ASYNC and test with stability (preferably with memtest86). Stay within 133 to 150 Mhz for the CPU and set a percentage where you can run your memory @ 200 FSB ASYNC. Set mem timings @ rated specs for Twinmos (x-x-x-cas 2.5). That's the only way to test your memory and be 100% certain that it meets its specifications.

If the memory fails on memtest86 @ rated specs (running ASYNC), then RMA ASAP.However, I'm pretty sure that you are being limited by your vdd volatage (chipset). I find hard to believe that two stick of twinmos would fail @ 185 or 190 Mhz.

Hope it helps

 

[markrb]

Since my last reply I have not been idle.
I have checked it out and I do have the A3 stepping.

I now fully believe it is the motherboard and not the memory that is holding me back.

I am currently working on getting the Iceberg cooler for the northbridge and after that is installed
I will do the VDD mod.

I am able to run 189Mhz in 64 bit mode with both modules installed, but drop to 185 or so in 128 bit mode with
no mods. This does not change with 1 or 2 modules, just 64 vs 128(DC) modes.

I am perfectly able to run the memory at 205Mhz if not higher in async mode. So if it truly is 205Mhz then it does clearly
reach it's advertised speed. So I guess the memory is actually doing just fine.

Mark

 

[neologan]

Yeah its obvious that the memory isn't the problem its the 8rda+ FSB. I doubt this northbridge heatsink will help you much, if at all. As a few have said before, you need a up the VDD volt from 1.7 upwards, there is a VDD mod around on some forums like extreme.net.

But these speeds your getting are really common untill you do the VDD mod, twinmos is good

neologan

Edit, oops, i saw your going to do the VDD mod, makes my post redundant, well good luck!