Ram question

[Carlos D]

Hi all,

I'm building my nas and I'm hesitating for the ram..

My nas will have low usage in general, 2 or 3 users max and will be mainly for reading. Will be writing to hdds every 3 days or so.

Here is what I have so far.

Case: Fractal Design Node 304
Motherboard: ASRock Rack Mini ITX DDR3 1333 Motherboards C2550D4I
HDD: will probably go for 3 x 3TB WD red depending on price.

I was considering getting used ram like this one.. (2 x 8gb used)
http://www.ebay.ca/itm/SAMSUNG-M393...123417?hash=item3d3db2a719:g:nHgAAOSwXetZOizj

Does it have to be compatible with the motherboard?
What's the average lifespan of server ram?
Any of you guys went for used ram?

 

[Spearfoot]

Hello, and welcome to the forums!

Does it have to be compatible with the motherboard?

Yes, indeed! The RAM absolutely must be compatible with the motherboard or it won't work at all.

What's the average lifespan of server ram?

That's a tough question. Generally, RAM doesn't fail very often - I've only had one RAM module fail in the course of 30+ years.

Any of you guys went for used ram?

Yes, but only for use in:

• A non-critical system
• As a component of a used server

Whether you buy new or (especially!) used RAM, make sure to run MemTest86 to thoroughly test it before putting it into service, as described in this post: "Building, Burn-In, and Testing your FreeNAS system".

Good luck!

 

[Carlos D]

Hello, and welcome to the forums!
Yes, indeed! The RAM absolutely must be compatible with the motherboard or it won't work at all.
That's a tough question. Generally, RAM doesn't fail very often - I've only had one RAM module fail in the course of 30+ years.
Yes, but only for use in:

• A non-critical system
• As a component of a used server

Whether you buy new or (especially!) used RAM, make sure to run MemTest86 to thoroughly test it before putting it into service, as described in this post: "Building, Burn-In, and Testing your FreeNAS system".

Good luck!

Thanks for all the info.

So to make sure that the used ram I was considering is compatible with my motherboard...

http://www.ebay.ca/itm/SAMSUNG-M393...db2a719:g:nHgAAOSwXetZOizj&afsrc=1&rmvSB=true

What specifications should I be looking at? I noticed it's DDR3 1600 ECC, is there anything else that would indicate that it's fully compatible?

Here's the link to my motherboard http://www.asrockrack.com/general/productdetail.asp?Model=C2550D4I

Thanks!

 

[Spearfoot]

Thanks for all the info.

So to make sure that the used ram I was considering is compatible with my motherboard...

http://www.ebay.ca/itm/SAMSUNG-M393...db2a719:g:nHgAAOSwXetZOizj&afsrc=1&rmvSB=true

What specifications should I be looking at? I noticed it's DDR3 1600 ECC, is there anything else that would indicate that it's fully compatible?

Here's the link to my motherboard http://www.asrockrack.com/general/productdetail.asp?Model=C2550D4I

Thanks!

I recommend purchasing memory listed in ASRock's 'Qualified Vendor List' for your board - it lists all of the RAM modules they've tested with the board. If you dig into the list you'll find part numbers which will help you find any available inventory on eBay or elsewhere.

 

[danb35]

Any of you guys went for used ram?

I just installed 128 GB of used RAM in my server this morning--32 GB DIMMs are expensive, and I could save some money that way. It's undergoing MemTest86+ testing right now.

Your motherboard takes DDR3 Unbuffered ECC PC-1600 or PC-1333 DIMMs (it also takes non-ECC, but you don't want to use those). Anything that meets those specs will likely be fine.

 

[Carlos D]

I just installed 128 GB of used RAM in my server this morning--32 GB DIMMs are expensive, and I could save some money that way. It's undergoing MemTest86+ testing right now.

Your motherboard takes DDR3 Unbuffered ECC PC-1600 or PC-1333 DIMMs (it also takes non-ECC, but you don't want to use those). Anything that meets those specs will likely be fine.

Thanks! Yea it's definitely not cheap. I understand that it's better to go for the recommended list from the manufacturer but I just wanted to make sure it will still work with a different one.

 

[Carlos D]

I just installed 128 GB of used RAM in my server this morning--32 GB DIMMs are expensive, and I could save some money that way. It's undergoing MemTest86+ testing right now.

Your motherboard takes DDR3 Unbuffered ECC PC-1600 or PC-1333 DIMMs (it also takes non-ECC, but you don't want to use those). Anything that meets those specs will likely be fine.

So for the specifications, I noticed there's 2 values..

• Speed which is in MHz
• PC-xxxx

e.g. 16GB 2x8GB DDR3 2RX8 1600MHz PC3-12800E 240pin ECC Memory Unbuffered

In the example above, I'm not sure what's the "PC3-12800E". Would this be compatible with my motherboard?

 

[Stux]

PC3 means DDR3
I assume the trailing E means ECC
The 12800 is how many MB/s can be transferred and is directly related to the clockspeed, Ie 1600MHz. DIMMs are 64 bits, which means 8 bytes can be transferred per cycle, which means 8 bytes per 1600mhz which means 12,800MB/s (ie 8x1600)

 

[Carlos D]

PC3 means DDR3
I assume the trailing E means ECC
The 12800 is how many MB/s can be transferred and is directly related to the clockspeed, Ie 1600MHz. DIMMs are 64 bits, which means 8 bytes can be transferred per cycle, which means 8 bytes per 1600mhz which means 12,800MB/s (ie 8x1600)

Thanks, and is there a difference between unbuffered and regular?
I just checked, so unbuffered is better for servers in general. So for a nas build does it make a big difference?

 

[Stux]

I just checked, so unbuffered is better for servers in general

I don't think that's correct.

Unbuffered means not registered (the buffer is the register). Registered means you can use higher capacity DIMMs. But not all boards can use registered memory.

By regular, you probably mean unbuffered

Use what your board/CPU supports.