Dual channel memory problem
 

Dear OC' Guru's
I'm currently working on a Gigabyte EP35-DS3 mainbord with a corsair dual channel kit CM2X1024-8500C5D (it's on the Gigabyte QVL list)
In single channel they work fine, no errors with memtest86+ v2.11
No errors after several passes.
When placed in Dual channel all hell breaks loose, random reboots, lots of errors within seconds with memtest.
I've set the timing and voltage correctly, but still same problem.
(The settings as adviced by "the ram guy" from the corair company)
Cas settings Cas 5-TRCD 5-TRP 5- TRAS 15
ACT to ACT Delay(tRRD) 5
Rank Write To READ Delay 5
Write To Precharge Delay 15
Refresh to ACT Delay 68 [Auto]
Read to Precharge Delay [Auto]
Static tRead Value [Auto]
Static tRead Phase [Auto]

However when I downgrade my memory to 800 everything works fine.

Even corsair doesn't have a clue what's causing the problems, the already replaced the RAM with brand new one's. So for now their solution is to replace them again. But i'm not that sure that will help...

So as far as I know it must be a DRAM timing setting.
I asked Gigabyte for some help, but I don't think even they understand the advanced DRAM timing settings, Cause my tech support question remains unanswered.
Hope you guys can help me out.
Many thanks already
Grtz

Are you running any OC ? Could be a mobo divider related issue... Strap selected ? MCH voltage ? better take some piccies of ya bios screens and link us to them plz...

Up the DDR2 voltage a bit, could help.

I added some 'piccie's' from the BIOS setup screen.
The settings in the pics are until now, the only one working in Dual channel memory config, unfortuantly @ 800 instead of 1066
I'm running currently no OC

Would it be safe to increase the voltage ? by, say 0.1v

Upping the voltage with 0.1V is safe. In your screenshot your memory voltage is already running 0.3V higher than normal.

//edit: the increased voltage (+0.3V) is normal for running the memory at 1066MHz, these modules are designed to run at 2.1V instead of 1.8V.

I would try to set Static tRead value 7-8, MCH OverVoltage Control +0.1, FSB OverVoltage +0.1 Probably the bios reads out the SPD wrongly and sets too tight timings...

If you set 1066Mhz and try with one dimm ? does that work ? If so swap the dimm for the other one and see if it works... if both pass try another dimm slot... and so on

I tought it might damage the hardware, cause corsair's advise is to run them at the voltage they are designed for, but I'll give it a go.

Then everything works fine, I explored every possibility.
even 2 dimm's in single channel are working fine.
Dual channel was tested in slot 1 & 3 and in slot 2 & 4 -->same problem:mad:

I'll give it a go, and will start a memtest when I'll go of to work.

Many thanks for all the advice so for.:ws:
I should have been a member for years on this forum:D

I fit works in single channel it's more of a NB problem... maybe the little bit more MCH voltage will do the trick. Could be it runs too hot too (place a small fan over it)

Too bad I don't see a strap setting in them screens, could be this is just a faulty divider... Have you tried flashing another bios ? Or tried another version of MemTest ?

I never really tested much DDR2 on P35/P45, but on P965 there were some issues with the first 5 subtimings (ACT to ACT -> Read to precharge).

Try putting them all except "Refresh to act" to 10 cycles instead if 4-4-8-4. Not saying this is definately going to work, just mentioning this because in some cases it did work :)

I've tried everything you guys suggested, but the problem persists.
-Latest BIOS version
-other version memtest
-increased the voltage of DRAM, CMH, FSB
-Modules in other slots
-set the first 5 subtimings to 10 (exept refresh to act delay)
-set Static tRead value to 7-8

I think we have to conclude it's a crappy mainboard ??

sorry to say yes... either live with it and run the rams at 800mhz C4 or buy another mobo..

ok I'll live with it for now.:mad:

You must read the answer I got from Gigabyte Tech support !:-p
They needed more than a week to answer, but the best is their reply...:no: :no:

Sent : 8/22/2009 02:22
Question : Dear support engineer,
My corsair dual channel kit CM2x1024-8500C5D (5-5-5-15)can't run in dual channel mode without problems; random reboots and failed memory tests with memtest86. In singel channel they run fine. no errors with memtest (28 passes)
I noticed the BIOS dedects the timing wrong, so i set the CAS-tRCD-tRP-tRAS to the right values. and raised the voltage to 2.1v (the right voltage fo these corsair modules.
How to set the advanced DRAM timings in the BIOS?
ACT to ACT Delay(tRRD) 4 [Auto]
Rank Write To READ Delay 4 [Auto]
Write To Precharge Delay 8 [Auto]
Refresh to ACT Delay 68 [Auto]
Read to Precharge Delay 4 [Auto]
Static tRead Value 6 [Auto]
Static tRead Phase Adjust 0 [Auto]

Could this be hardware failure of the motherboard ?

I sincearly hope you guys can clear this matter out.
Even corsair doesn't now what the correct settings are.
Thank you in advance

------------------------------------------------------------------


Dear Sir,

Thank you for contacting GIGABYTE.
Please make sure that you load optimized defaults and set the Memory Voltage to 2.1 volts and then set the timings to 5-5-5-15 (CAS-tRCD-tRP-tRAS) and then test the modules one at a time with www.memtest.org! Please allow memtest to run 2-3 passes on each module.

Best Regards,

-----------------------------------------------------------------------

Thanks for your answer, but did you actually read my question ?
Cause you are just the repeating the question disguised as an answer.
In you take a look at the attachments, you can see those settings are already applied. (and yes, i set the optimized deafaults first)
So i will rephrase my question, to make it simpler.
How to set the advanced DRAM timings ?
ACT to ACT Delay(tRRD) 4 [Auto]
Rank Write To READ Delay 4 [Auto]
Write To Precharge Delay 8 [Auto]
Refresh to ACT Delay 68 [Auto]
Read to Precharge Delay 4 [Auto]
Static tRead Value 6 [Auto]
Static tRead Phase Adjust 0 [Auto]

Nobody seems to what these settings are for... they aint just for fun, aren't they ?

Could this be a faulty Mainboard ???

It still could be an SPD issue, run 1066mhz with one dimm and download MemSet in windows, write down all them values and compare with the bios AUTO settings. Set them settings manually and pop in the 2nd dimm

Other thing you could try is to OC the FSB a bit : eg 7 x 400 with rams at 1000/1066mhz and see if she runs then. (this to see if it's a crappy divider)

If it's still a no go mate, either run the rams below specs or grab yaself another mobo... too bad these things still happen

It's especialy sad that these things happens with memory modules tested and approved by the motherboard manufacturer !

Something similar happened to me.

I was (and am) running 4x1GB of Kingston HyperX PC8500 DDR2 on an Asus P5K-E Wifi mobo.

The RAM is supposed to run at 1066MHz, but Kingston has put the SPD to 800MHz because at the time when they released that RAM, few mobo's were able to read an SPD of 1066MHz.

As a result, the memory is being recognized by the BIOS as being 800MHz RAM. Everything worked just fine, running XP-Pro 32-bits.

When I saw that the RAM was running at 800MHz, I went into the BIOS and manually cranked it up to the 1066MHz at which is was supposed to run. But that resulted in my OS behaving like a drunk in a liquer-store after closing time. I got more blue screens in an hour than Michael Schumacher had fastest laps in his career.

Since I didn't change anything else, I of course was pretty certain that the BSoD were due to me tinkering with the RAM's speed, so I reverted back to 800MHz, and yep, all was fine again.

The funny thing is, since I switched from XP to Windows 7 32-bits, the memory is still recognized as being 800MHz RAM, but when I run it at 1066, my OS stays stable. I even reached speeds of 1140MHz, without having to tweak voltage or anything. Except that at such a speed, after a couple of hours, my video card (Asus EN8800GTS 512MB Top) starts acting weird and sometimes stops sending data to the monitor (monitor stays 'on', with its light blue, but there's no picture). I've reverted back to the 'stock' speed of 1066MHz under Win7 and haven't had any kind of problem with my RAM...

And I must emphasize the fact that no hardware or software was changed when making the switch from XP to Win7... so go figure.

??? they are just selected dimms that should work 100% together in dual channel config James ??? No idea why you started technical :p

@ Phunk thats the same ram i have in my AM2+ machine heres what mine says via Everest 5.30

Field Value
North Bridge Properties
North Bridge AMD K10 IMC
Supported Memory Types DDR2-400 SDRAM, DDR2-533 SDRAM, DDR2-667 SDRAM, DDR2-800 SDRAM, DDR3-800 SDRAM
Revision 00
Probe Filter Not Supported

Memory Controller
Type Dual Channel (128-bit)
Active Mode Dual Channel (128-bit) - Ganged

Memory Timings
CAS Latency (CL) 5T
RAS To CAS Delay (tRCD) 5T
RAS Precharge (tRP) 5T
RAS Active Time (tRAS) 15T
Row Cycle Time (tRC) 22T
Command Rate (CR) 2T
RAS To RAS Delay (tRRD) 4T
Write Recovery Time (tWR) 10T
Write To Read Delay (tWTR) 4T
Read To Precharge Delay (tRTP) 6T
Four Activate Window Delay (tFAW) 18T
Write CAS Latency (tWCL) 5T
Refresh Period (tREF) 7.8 us
DRAM Drive Strength 1.25x
DRAM Data Drive Strength 1.0x
Clock Drive Strength 1.5x
CKE Drive Strength 1.5x
Idle Cycle Limit 16

Memory Slots
DRAM Slot #1 1 GB (DDR2-800 DDR2 SDRAM)
DRAM Slot #2 1 GB (DDR2-800 DDR2 SDRAM)
DRAM Slot #3 1 GB (DDR2-800 DDR2 SDRAM)
DRAM Slot #4 1 GB (DDR2-800 DDR2 SDRAM)

but the 1066MHz setting are not stored in the SPD under the normal JEDEC profile settings they are stored in the SPD as an EPP setting (Enhanced Perfomance Profile)

Field Value
Memory Module Properties
Module Name Corsair Dominator CM2X1024-8500C5D
Serial Number 00515958h (1482248448)
Module Size 1 GB (1 rank, 8 banks)
Module Type Unbuffered DIMM
Memory Type DDR2 SDRAM
Memory Speed DDR2-800 (400 MHz)
Module Width 64 bit
Module Voltage SSTL 1.8
Error Detection Method None
Refresh Rate Reduced (7.8 us), Self-Refresh

Memory Timings
@ 400 MHz 5-5-5-18 (CL-RCD-RP-RAS) / 23-51-3-6-3-3 (RC-RFC-RRD-WR-WTR-RTP)
@ 270 MHz 4-4-4-13 (CL-RCD-RP-RAS) / 16-35-3-5-3-3 (RC-RFC-RRD-WR-WTR-RTP)

Enhanced Performance Profile
Profile Name High Frequency
Optimal Performance Profile Yes
Memory Speed DDR2-1066 (533 MHz)
Voltage 2.1 V
Memory Timings 5-5-5-15 (CL-RCD-RP-RAS)
Row Cycle Time (tRC) 22T
Command Rate (CR) 2T
Write Recovery Time (tWR) 8T

Memory Module Features
Analysis Probe Not Present
FET Switch External Disabled
Weak Driver Supported

Memory Module Manufacturer
Company Name Corsair Memory, Inc.
Product Information http://www.corsairmemory.com/products/xms_home.aspx