how close does RAM have to match?

[kcwalker]

I've always bought RAM in matching pairs, and now find that's hard to do for my old Dell Precision T3500 with 12 GB RAM (OEM installed). There are 3x 4GB DIMM, and 3 open slots. Max RAM/slot is 4GB.
I'd like to add 3 more 4GB DIMM (increase to 24 GB total).
Existing RAM is Hynix 4GB 2Rx8 PC3L-10600-E-9-10-E0
I can't find this exact specification (but can get close).
How close is close enough to work?
Will these work (one non-ECC and one ECC);
Kingston ValueRAM 4GB 1333MHz DDR3 Non-ECC CL9
or
OWC 4.0GB PC10600 DDR3 ECC-R 1333MHz

 

[COLGeek]

The closer the better, if you can't find identical memory modules. Keep in mind that you cannot mix ECC with non-ECC memory. It must be one or the other.

Given that you have 12GB now (that is more than enough for most users), why do you want to add more?

 

[kcwalker]

Thanks for the note. I was considering non-ECC, so I avoided a big screw-up. Unfortunately, ECC adds some $$$. :-(
Why go from 12 to 24 GB? The system is used for engineering work (CAD/FEA). 12 GB is enough for basic problems, but more is better for large problems. (I've run my biggest problems on an 8 processor Linux system w/ 296 GB RAM.)

 

[kcwalker]

I found something very similar listed on Ebay, marked:
Hynix 4GB 2Rx4 PC3L-10600R-E-9-10-E1

Seller lists as ECC memory (don't know what the 10600R means).
Sold as set of 4 (16 GB total).
Is this compatible with 2 DIMMS in OP (2Rx8 PC3L-10600-E-9-10-E0)

 

[truegenius]

296GB ram !
my computer have less HDD than that :lol:

btw you can use cpu z software to check fastest jedec spec supported by your current ram and can buy ram close to those settings

all your ram will run at slowest ram's speed so anything will be compatible

according to the name of your ram, it looks like it have exactly kingston value ram's timing and speed so you can go for kingston

 

[COLGeek]

The R means registered. You should not mix registered and non-registered (unbuffered) ECC memory.

Understood on your needs. Been there myself.

Good luck.

 

[kcwalker]

Thanks COLGeek. I replied earlier but don't see my post.
I think I got it; there are 3 categories:
1) Uunbuffered (non-ECC), 2) ECC (non-registered), and 3) ECC Registered
The 3 can't be mixed.
My Dell T3500 currently has ECC and can also use unbuffered (but NOT registered).
So, either I find 3x4GB ECC (non-reg), or buy all new 6x4GB non-ECC.

I found this:
Kingston KR1P74-HYB ECC DDR3 PC3-10600
Chips marked:
4GB 2Rx8 PC3L-10600E-9-10-E10
I think it's ECC non-registered, but not sure.

This is really close to my DELL OEM RAM.
[Existing RAM is Hynix 4GB 2Rx8 PC3L-10600E-9-10-E0]

Does this sound like it's compatible?
Thanks!

 

[COLGeek]

That does appear to be unbuffered RAM. It seems worth a shot. Good luck!

 

[kcwalker]

Unbuffered, as in non-ECC, eh? Shoot, I need ECC non-registered to match. :-(
I bought it, so guess we'll find out when it arrives. 🙂
Is there a test I can run to determine ECC vs non-ECC once it's installed?
Thanks!

 

[COLGeek]

Use CPU-Z to identify exactly what you have now. Get it here:

http://www.cpuid.com/softwares/cpu-z.html