Ram will only work in single channel

[bubba50]

I just added a 2 512mb sticks of ram to my computer and it will only come up as single channel. my question is how do i make it work in dual channel mode if possible and if not should i keep it anyway or keep on looking for ram that will work in dual channel mode on my dell. This is the second time i have ordered ram the first one i tried was corsair value select which i had to rma because it didn't work at all. Here is all the information i have on my computer.

I have a dell dimension 4600
bios A12 i use a phoenix bios whatever that means
P4 3.0ghz 800mhz fsb
graphics ati radeon x1300 pro
865gv chipset i don't know who my mobo manufacturer is i called dell but they didn't know.
memory for existing ram 2x256 mb pc 3200 ddr 400 cl 3 manufacturer nanya.
Ram i purchased 1 pair 2x512mb pc 3200 ddr 400 cl 3 manufacturer infineon.

I don't know the voltage for either of them. The ram i bought works fine it just isn't in dual channel mode.

 

[lost]

The 865 chipset should support dual channel but I'm not sure if Dell does something with this.

If you have the 256Mb and 512Mb "sticks" in all four sockets (Channel A and B), it will not operate in dual channel mode.

To operate in dual channel all memory "sticks" have to be the same size and type and in the correct channels.

One each of the 512Mb "sticks" has to be in channel A and B - DIMM 1 and DIMM 3 OR DIMM 2 and DIMM 4 to work in dual channel. .

Take out the 256Mb "sticks" if you have them installed, you can't use them with the 512Mb "sticks", and make sure the 512Mb "sticks" are in the usually same coloured sockets.

BIOS automatically assigns dual channel or not.

 

[bubba50]

I already tried installing just the 2 512 sticks and they still came up as single channel. i put them in dimms 1 and 3. From what i read different ram sizes should still work in dual channel. The only thing i can think of is it's either the voltage setting or the bios setting. Regardless the ram works it just doesn't work in dual channel mode.

 

[bubba50]

You said bios automatically assigns dual channel does that mean there is no way to get around the single channel issue and if so should i just rma it and try my luck with another ram vendor.

 

[leckig]

One each of the 512Mb "sticks" has to be in channel A and B - DIMM 1 and DIMM 3 OR DIMM 2 and DIMM 4 to work in dual channel. .

Take out the 256Mb "sticks" if you have them installed, you can't use them with the 512Mb "sticks", and make sure the 512Mb "sticks" are in the usually same coloured sockets.

Are you sure? I have 2 256 sticks and 2 512 sticks and my comp rund in dual channel just fine!

 

[Mondoman]

...

To operate in dual channel all memory "sticks" have to be the same size and type and in the correct channels....

Not true -- it all depends on the motherboard.

 

[Mondoman]

You said bios automatically assigns dual channel does that mean there is no way to get around the single channel issue and if so should i just rma it and try my luck with another ram vendor.

bubba:
Running in dual-channel mode is a property of the motherboard, NOT the memory modules. Some MBs won't run in dual-channel mode, others need matching DIMMs in the correct slots to do so, and others will take just about anything and do so.
There is no general rule. It all depends on your specific motherboard.
1) Look in your MB manual.
2) If it doesn't describe how to arrange memory for dual-channel mode, call your MB manufacturer (Dell in this case).
3) If neither the MB or manufacturer can tell you, chances are the MB can't run in dual-channel mode. You can experiment: start with a pair of identical DIMMs and install them in all 6 possible ways in the 4 memory slots. If one of the arrangements runs in dual-channel mode, then add your other pair of DIMMs in the other two open slots.
If none of the 6 configs works for the initial pair, then your MB won't run in dual-channel mode, and trying different RAM won't fix it.
So, no need to RMA anything, just try some configs to see if your MB supports it.

 

[Dahak]

Dual channel only works when you have two(2) sticks of ram installed.As soon as you install a third stick or more,it switches back to single channel.I do not know why this is but I know that's the way it is.Goodluck.

Dahak

primary gaming rig
AMD X2-4400+@2.4 S-939
EVGA NF4 SLI MB
2X EVGA 7800GT CO IN SLI
2X1GIG DDR IN DC MODE
WD300GIG HD
EXTREME 19IN.MONITOR 1280X1024
ACE 520WATT PSU
COOLERMASTER MINI R120

secondary gaming rig
GYGABYTE MB AGP
AMD X2 3800+ S-939
2X512 DDR IN DC MODE
X1650PRO 512 AGP
17IN.MONITOR
MAXTOR 120GIG HD
450WATT PSU

 

[Mondoman]

[wrong info snipped]...I do not know why this is but I know that's the way it is.

Dahak,
Please do some more research before spreading misinformation.

 

[lost]

While I agree with some of your points, I would suggest you read the o/p's original post.

The 865 chipset is no 965 chipset.

 

[bubba50]

Mondo u said there r 6 configurations can u please tell me what they r.


My original ram works in dual channel mode.

I will call dell and c what they say.

 

[ThePimp]

While I agree with some of your points, I would suggest you read the o/p's original post.

The 865 chipset is no 965 chipset.

The 865 chipset is the same that was on my old P4P800 motherboard & ran dual channel with no problems with 2 different capacity modules. As long as the 2 different sets of modules were in the correct slots for each channel it made no difference (i.e. 2 x 512 in slots 2 & 4 and 2 x 1024 in slots 1 & 3) and ran in dual channel mode. Same goes for my A8N-SLI Deluxe that I am typing this message on currently.

To the OP, try downclocking the memory speed in the BIOS to DDR333 capabilities (if the Dell BIOS allows you to) as some boards would only run in Dual Channel mode if all 4 slots were populated (this was a problem on some 865 based motherboards and was fixable with a BIOS update with the required changes made in it).

 

[bubba50]

I don't know how to get to the bios, is that the system setup where i press the f2 key when i first turn on my computer. If it is it will not let me do that.

 

[leckig]

that would be it!

 

[joefriday]

Same thing happened to my with my pair a 256mb pc2700 sticks. I downloaded a program and looked at an Intel (or was it Micron?) white sheet that told of what parameters in the memory needed to be the same in order for the memory to run in dual channel. The program than look at all my settings written into the memory SPD so that I could see what it was tha t was different. There's also a program out there that will allow you to modify the SPD, to force a dual channel compatibility, but I wouldn't recommend it. I'll look up the stuff again later and get back to you on it.

 

[Mondoman]

While I agree with some of your points, I would suggest you read the o/p's original post.

The 865 chipset is no 965 chipset.

I was assuming you meant in general, not just 865GV chipset boards.

Of course, it does still depend on the specific motherboard, because not all implement dual-channel mode (especially in cheaper boards).

However, I was able to find this Intel document (www.intel.com/design/chipsets/Dual_DDR_SB.pdf) that says that the 875P, 865G, and 865PE chipsets do NOT need all 4 modules to be the same size to run in dual channel mode. As long as each pair spanning 2 channels is the same size, you're OK.
Since the 865GV uses the same memory controller hub as the 865G, surely the above applies to 865GV chipset-based computers as well.

 

[Mondoman]

Mondo u said there r 6 configurations can u please tell me what they r.
...

If you name the 4 memory slots A through D, the configs are:
Config 1: DIMM in A, DIMM in B, C empty, D empty
Config 2: DIMM in A, B empty, DIMM in C, D empty
Config 3: DIMM in A, B empty, C empty, DIMM in D.
Config 4: A empty, DIMM in B, DIMM in C, D empty
Config 5: A empty, DIMM in B, C empty, DIMM in D
Config 6: A empty, B empty, DIMM in C, DIMM in D.

 

[Mondoman]

joef, this varies from MB to MB, so it's probably best if we stick to the OP's specific case. We don't know his MB model, but his chipset does support dual-channel mode using 2x256MB + 2x512MB sticks.

 

[joefriday]

Alright, I finally get around to finding all the stuff I needed when I researched the same problem. Download the following things. Read Micron's datasheet very closely, as it explains what has to be compatible in order for two dimms to run in dual channel on an i865 chipset. Next, use the SPD reader program to look at all the values in the SPD for each ram stick. Compare the SPD values of those indicated in the Micron data sheet to be necessary for dual channel compatibility. I guarantee you one of those values will not match between the two sticks, and now you've identified EXACTLY what the problem is. Now the last tool is if you're brave, you can try to edit the SPD on one of the dimms so that is matches the other at the required SPD entries. I don't recommend it unless you don't care if you possibly FUBAR one of your ram sticks. Anyway, changing the values of one of the SPDs will make the two dual channel compatible, providing the modified SPD doesn't render the dimm a paperweight. Good Luck.

Micron datasheet on dual channel mode of Springdale and Canterwood chipsets, see page2, Table 2:
http://download.micron.com/pdf/technotes/TN0452_A.pdf

SPD reader, us it to check the important SPD bytes of your dimms to see if they match:
http://www.majorgeeks.com/DocMemory_SPD_Reader_d4383.html

SPD viewer and Editor. Use at your own risk.
http://www.techpowerup.com/spdtool/SPDTool_055.zip

graphics ati radeon x1300 pro
865gv chipset i don't know who my mobo manufacturer is i called dell but they didn't know.

The i865GV does not have an AGP interface (see page 222 of Intel datasheet). From that fact alone I can assure you that you must have an i865G chipset. Only aftermarket companies produce freak of nature mobos that would pair the i865GV with an AGP slot (ie Asrock's 775i65GV, notice how they call it A.G.I.?). Since Dell doesn't break Intel's design rules, you're definitely not using an i865GV chipset.

joef, this varies from MB to MB, so it's probably best if we stick to the OP's specific case.

My motherboard uses the i865G chipset. My dual channel incompatibility problem is very likely the same as his.

 

[bubba50]

Ok what is an spd. Yes my mobo has an agp interface.

When i called dell this is all they said about my mobo
80532 865gv i don't know what 80532 is.

 

[Mondoman]

... Now the last tool is if you're brave, you can try to edit the SPD on one of the dimms so that is matches the other at the required SPD entries.

Definitely do NOT do this, since the SPD data we are talking about reflects the physical characteristics of the DIMM. You can't just go in and tell the computer, for example, that the DIMM has 2 ranks, not 1, and expect it to work. It would be like sticking a "diesel OK" sticker on a gasoline car and expecting it to suddenly work with diesel fuel.

bubba, are the two pairs of DIMMs you have matched pairs? That is, are the two DIMMs in each pair identical? If so, they should be fine for dual-channel mode.
Also, what is the result of trying the 6 different configurations with just one pair of DIMMs?

 

[lost]

865G/GV chipset.

865G = AGP

865GV = On Board Graphics - No AGP.

Found this from Intel:

If either only channel A or only channel B is populated, the GMCH is set to operate in singlechannelmode. Data is accessed in chunks of 64 bits (8 B) from the memory channels. If bothchannels are populated with uneven memory (DIMMs), the GMCH defaults to virtual singlechannel(VSC) mode.

Even with similar memory configuration on both the channels, it is possible
to force the GMCH to operate in single-channel mode, which by default is configured as Lock Step mode.

The GMCH behaves identical in both single-channel and virtual single-channel modes(hereafter referred to as single-channel (SC) mode).


It is interesting that it says that even with simmilar memory config it is possible to force to operate in single channel mode.

Like I said you don't know what Dell has done.

 

[joefriday]

Dell's 4600 is configured from the factory in dual channel mode, so at least it's not like Dell permanently disabled dual channel capability.

 

[lost]

This is a link to the Intel Datasheet for the 865G/865GV.

http://download.intel.com/design/chipsets/datashts/25251405.pdf


Dell or whoever the mobo manufacturer is may have changed its "features" to suite.

 

[lost]

I suggest you try something like this:

http://www.nextag.com/4600-dell-dimension-memory/search-html

BIOS in simple terms, reads the spd - serial presence detect on the memory module and reads the chipset to assign memory operation- like I said very over simplified explanation.

Maybe you need memory that works only? with your setup.

Hope the link helps.