# [SOLVED] Corsair 4gb module upgrade not working on m4a785td-v evo



## sticksNstones (Nov 1, 2011)

Hi all. A situation concerning a new upgrade in memory is driving me round the bend. I have just bought 4gb Corsair XMS3 (CMX4GX3M1A1333C9) to accompany 2 x 2gb Corsair XMS3 modules (to take me to 8gb total). Once the new memory is installed on my Asus m4a785td-v evo mobo, I turn the PC on and nothing happens. No bleep, no bios, no windows.

Initially I thought it was faulty ram so I sent it back to Corsair and have received the new ram from them which is 99.99999% likely to be fine. I have tried the new ram on its ownio, with a single module of the other ram and, again, nothing happens when I power on. After reading the Asus manual, the mobo can accommodate 4gb RAM modules with a maximum capacity of 16gb ram, though this particular 4gb ram module is not included in their suggested list of compatibles yet I've read not to take Asus' compatible memory types too seriously, as some of their 'compatible memory' does not work in some people's systems. So, I'm having a major head scratching time of it and hoping some one could please help me out. Is there a setting in the BIOS which needs changing? I am at a loss.

My system: AMD Phenom x4 II 955, Asus m4a785td-v evo, 4gb (2x2) Corsair XMS3, 640 Barracuda HDD, Corsair 500w power supply.


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## greenbrucelee (Apr 24, 2007)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*

well could be down to the fact the you were running in dual channel (2x2GB in matching slots) then you have added the new 4GB module which takes you to single channel plus the fact the 4GB stick is likely a different voltage to the other two sticks.

You should always run matchin ram to avoid problems that goes for speed,size and timmings.


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## sticksNstones (Nov 1, 2011)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*

I've checked the voltage and latency of both modules - both are the same, 9-9-9-24 latency and 1.5V. Due to this, is it likely down to using both single and dual channel? You'll have to forgive much of my ignorance, as I don't know too much about the inner workings of computers.


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## greenbrucelee (Apr 24, 2007)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*

i see no mention of this system on the asus qvl list of that baord being able to take one stick of 4GB ram it runs in dual channel only i.e 2 dimms.


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## Tyree (May 10, 2009)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*

Do you have a need for more than 4GB of RAM" No games and few apps can utilize over 3GB. Adding that single stick has most likely put you in Single Channel Mode and performance will be degraded. Problems with 4GB RAM sticks is also not uncommon.
Mixing RAM (even when the specs are identical) can cause problems. Have you tried using only the new stick to be sure it's not problematic?


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## sticksNstones (Nov 1, 2011)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*

Thanks for the responses. I think, after further research, the mobo cannot accommodate 4gb modules since, yes, I have tried the new 4gb ram on its own in all memory bays and the PC remains completely unresponsive. A mistake on my part, thus I will get my hands on the identical 2gb ram (Corsair TW3X4G1333C9 XMS3 4gb set) which has been living in my computer the past few years.

Hopefully that'll take me up to 8gb ram without any problems. I mainly use the PC for photo and video editing and have found the PC to be struggling with some of the programs I currently use so 8gb would be beneficial.


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## MattCharman (Oct 28, 2011)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*



sticksNstones said:


> I think, after further research, the mobo cannot accommodate 4gb modules


Although slightly outdated, the Qualified Vendor List for your board does show it supports 4Gb modules - it specifically lists a 4Gb Samsung module. 
http://uk.asus.com/Motherboards/AMD_AM3/M4A785TDV_EVO/#MSL

Your board also states it supports a single DIMM in any slot, and will run in single channel mode, and supports up to 16Gb which would have to be in 4Gb DIMMs as there are 4 slots.

From the QVL:


> • A*: Supports one module inserted in any slot as Single-channel memory configuration
> • B*: Supports one pair of modules inserted into eithor the blue slots or the black slots as one pair of Dual-channel memory configuration
> • C*: Supports 4 modules inserted into both the blue and black slots as two pairs of Dual-channel memory configuration


The 4Gb Samsung module has a mark that it can be used as A,B and C.


It may be just an incompatibility. Do you have the latest BIOS update for the board?


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## Tyree (May 10, 2009)

*Re: Corsair 4gb module upgrade not working on m4a785td-v evo*



sticksNstones said:


> Thanks for the responses. I think, after further research, the mobo cannot accommodate 4gb modules since, yes, I have tried the new 4gb ram on its own in all memory bays and the PC remains completely unresponsive. A mistake on my part, thus I will get my hands on the identical 2gb ram (Corsair TW3X4G1333C9 XMS3 4gb set) which has been living in my computer the past few years.
> 
> Hopefully that'll take me up to 8gb ram without any problems. I mainly use the PC for photo and video editing and have found the PC to be struggling with some of the programs I currently use so 8gb would be beneficial.


Good choice and good luck.


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