4gb mem=lower speed?

[keith97]

I have a new build using vista64 and have added another 2gb of ram to give me a total of 4X1gb corsair 800mhz cas4. I was running the first pair at 900mhz 44412@ 2.1v no prob.

Since I added 2 more sticks the mem will only run at 700mhz. Why won't it run at specs now?

I also enabled the sli mem feature in my bios (asus p5n32-e sli plus). I turned it on EXPERT. What does this do if I manually set timings?

Can someone please help?

 

[memorymaster]

That is weird why you can only run at 700 MHz with the 4 sticks in. Maybe it has to do something to do with the board itself, as I do not have much experience with 4GB of RAM spread over 4 sticks...

Anyways, the sli is a feature that reads the overclocked settings from the spd instead of the JEDEC standards (highest standard is set at 800 5-5-5-15). When you enable the sli, the bios will read then read the memory at the overclocked settings that cosair is advertising. If the sli is on expert, you can then overclock the memory manually to try to get the best performance possible.

So, sli is very helpful with beginning overclockers, but as people become more advanced, sli is less useful, since an experienced overclocker would just change the settings manually.

 

[keith97]

I have tries to relax timings to 55515 and 2.2v but it didn't help at all. I have run the vista Memory Diagnostics Tool and everything was fine.

I guess it might be the new mboard like you said. Hopefully asus will have a bios update to address this.

BTW-vista uses 1gb now just idling at desktop. The 4gb does make things a little snappier, especially at bootup.

 

[Mondoman]

It is not unusual to have a motherboard be unable to run 4 modules of RAM at the same max speed that 2 modules can be run at. Sometimes this is a MB issue, sometimes it is a RAM issue (since all the RAM in the system has to run at the same speed, it will run at the speed of the slowest installed RAM).

Try installing only the new RAM and see how fast it will go. If it will also run at DDR2-900 on its own, then it's probably a MB issue. If so, and if your MB is spec'd to run 4 modules at DDR2-900 under the voltage/timing conditions you listed, then you should be able to get a free replacement under warranty. More likely, it is spec'd to run at DDR2-800 max; you'll have to look into the details to see if you're actually exceeding the MB specs or not.

 

[MadHacker]

BTW-vista uses 1gb now just idling at desktop. The 4gb does make things a little snappier, especially at bootup.

vista 32bit or 64 bit?

 

[keith97]

Both pairs of modules will run 900mhz when used as a pair at spec timings. Its only when all four are running together. I can even run 3 sticks without any prob.

Both mb and mem are supposed to run 800mhz at 44412 2.1 v.
Could it just be that its just a new mb needing some bios refinement.

Vista 64

 

[Schrovan_Rip]

In order to address 4gigs his version of Vista has to be 64bit.

 

[darkguset]

I have a new build using vista64 and have added another 2gb of ram to give me a total of 4X1gb corsair 800mhz cas4. I was running the first pair at 900mhz 44412@ 2.1v no prob.

Since I added 2 more sticks the mem will only run at 700mhz. Why won't it run at specs now?

I also enabled the sli mem feature in my bios (asus p5n32-e sli plus). I turned it on EXPERT. What does this do if I manually set timings?

Can someone please help?

It sounds like you are running your memory on Command Rate 1. The memory controller can handle 2 sticks at that timing, but when you add another 2 sticks bringing the total to 4, the Command Rate needs to be changed to the value of 2 for the controller to be able to cope with the extra addressing.

Hope that is your problem.

 

[keith97]

Yea, i tried the command rate of 2t when I loosened timings to 55515 and it wouldn't even go to bios, had to remove one stick and everything was ok. I even moved the sticks around (in pairs) and same prob.

Will increasing volts help and how high can I safely go with this mem. I already tried 2.2 and it didn't help.

Thanks for your help

 

[Mondoman]

Sounds like a motherboard issue. Time to contact tech support.

 

[darkstar782]

Even with the on-die termination of DDR2, there is still some signal refelction with multiple DIMMs. The more DIMMs on a controller, the worse it gets.

You wont get the same RAM overclock with 4 DIMMs as with two, although 200MHz, taking you below stock, seems a large jump...

 

[memorymaster]

To answer the question about voltage... the most you ever want to go with memory is usually 2.4V. But with only overclocking to 800 or 900 Mhz at relaxed timings, the highest range would be 2.1V to 2.2V. So, I would not increase the voltage any higher since I do not think it will help your problem.

BTW... Usually you would only go to 2.4V on micron chips, as they easily take the most power out of any other chip out there.

 

[darkstar782]

Yes, Micron D9's ftw

Most DDR2 these days is rated at 2.1v or 2.2v though, I wouldnt worry about 2.2v on any RAM myself.

 

[keith97]

Most it will run is 735mhz 4-4-4-12 1t at 2.1v. 740mhz it will lock up before bios despite relaxed timings and fiddling with voltage so it must be mother board limit.

My first build so I'm still figuring things out, Thanks for all the tips.