Sorry odd question, I have been running my server without issue for a while now.  This past weekend I upgraded form 5.0 to 5.05, with the new shiny features I noticed that the 4 gigs of ram I have been using were almost 100% utilized.  I went ahead and ordered two more identical (supposedly) sticks of ram giving me a total of 8 gigs.  Everything should have been fine however I cannot get past post and I'm getting those fun memory issue repeating beeps.  I've tried every configuration I could so each channel was the same and I've even swapped one set for the other which boots just fine, so I suppose the new memory sticks are just fine.  Any help to get past post would be greatly appreciated.

Did you check with your motherboard manual to see how much memory (and configuration) your motherboard supports? 

 

Did you check on both the memory and motherboard manufacturers' websites to see what memory is recommended for your motherboard?

 

Oh, and double check by visually checking the original memory sticks to make sure that they are what you think was actually in the board!

The mother board supports 16 gigs of memory and its the exact same memory modules that I was using successfully before.

Hard to say without the specifics of your motherboard or the memory.

 

But it's not uncommon to have issues with 4 modules installed in an unbuffered board.    Post the make/model of your motherboard and the details on your RAM modules.    Sounds like a possible voltage issue with the modules (if they require higher-than-standard voltage, then one pair may work; but when you install both the voltage drops below the minimum threshold of the modules);  or possibly just a loading issue which will require adding a cycle or two to the latency settings.

 

But rather than guess, post the specific details.

 

Hard to say without the specifics of your motherboard or the memory.

 

But it's not uncommon to have issues with 4 modules installed in an unbuffered board.    Post the make/model of your motherboard and the details on your RAM modules.    Sounds like a possible voltage issue with the modules (if they require higher-than-standard voltage, then one pair may work; but when you install both the voltage drops below the minimum threshold of the modules);  or possibly just a loading issue which will require adding a cycle or two to the latency settings.

 

But rather than guess, post the specific details.

 

+1, please give us your hardware specifics. I maybe a total unRAID n00b but I have built a fair few computers! Might be able to help.

I have two observations...

 

It is very normal for almost 100% of the installed memory to appear to be used, because Linux takes it for buffers / cache etc.  That memory is then freed up for other things as required.

 

It is also quite common for mother boards to need to run the RAM maybe one speed slower if there are four modules installed.  Some mother board makers RAM lists specify a slower clock for 4 rather than 2 sticks of the exact same type.  The way I have occasionally done this is to boot with two sticks and change the RAM speed settings in the BIOS to manual, and then choose a slower RAM clock speed (so PC1333 for PC1600 RAM, for example).  Then power off so that the second pair of sticks can be installed and they will often work just fine.  Due to the lower cycle counts in RAM timings for slower clock speeds, there is normally not as much reduction in system performance as you might expect from the RAM clock speed reduction.

I appreciate everyone's advice, I think what happened was that even though the Crucial memory had the same part # this modules were in fact different.  I chose to return the modules and upgrade with larger sticks (if needed) at a later date.  Thanks again.

Since your motherboard supports 16GB, you can use 4GB modules.    If you decide to upgrade in the future, the best choice would be to replace your current modules with a pair of 4GB modules -- that would let you double your memory without increasing the load on the memory bus (i.e. you would still just have two modules installed).