Need help buying the right RAM

vbcda

Junior Member
Nov 14, 2014
6
0
0
Hey,


I need to add an extra 4GB of RAM to my laptop which has a 4GB stick. I'm a little worried about latency matching, so need your help with that.


Here's the specs of the RAM I've got,
11-11-11-28 latency
1.5 Volt
204 pins
1600 MHz



So far I've found 2 RAM sticks I like, and both of them have the same speed and voltage, but differ in latency.


One has a latency of 11-11-11-30 and the other has 9-9-9-24. Which of these should I go for ? Will it be able to work smoothly with the other RAM I've got ?



Or should I play safe and buy the RAM that has the same latency figures as mine.


Thanks.
 

mikeymikec

Lifer
May 19, 2011
21,005
16,257
136
Finding compatible RAM is more than just matching the figures up; some brands are more compatible than others. In the case of a laptop I normally just use Crucial's system picker and pick the RAM capacity I require.
 

vbcda

Junior Member
Nov 14, 2014
6
0
0
Finding compatible RAM is more than just matching the figures up; some brands are more compatible than others. In the case of a laptop I normally just use Crucial's system picker and pick the RAM capacity I require.


Even I tried doing the same, unfortunately my laptop isn't listed there. Even the kingston tool dint help.
 

mikeymikec

Lifer
May 19, 2011
21,005
16,257
136
What's the laptop model and manufacturer? Also, what model number codes are written on the under side?
 

mikeymikec

Lifer
May 19, 2011
21,005
16,257
136
That exact one isn't on Crucial UK, but there are ones that end with -A02US and -A07UK, comparing the results of both of those, as far as memory goes their requirements are the same.

Part #CT3628296 looks like the one you want.

PS - I'm looking on the UK site, but I suspect the only difference is the currency symbol :)
 

vbcda

Junior Member
Nov 14, 2014
6
0
0
That exact one isn't on Crucial UK, but there are ones that end with -A02US and -A07UK, comparing the results of both of those, as far as memory goes their requirements are the same.

Part #CT3628296 looks like the one you want.

PS - I'm looking on the UK site, but I suspect the only difference is the currency symbol :)

Tried that, but the ones recommended don't seem to be what I'm looking for. There's a difference in voltage, all suggested ones work on 1.35V whereas I need 1.5V RAM's.
 

mikeymikec

Lifer
May 19, 2011
21,005
16,257
136
I doubt that's actually a problem since I haven't experienced Crucial making a compatibility mistake with their products (and I have bought quite a few modules from them for customers).
 

BonzaiDuck

Lifer
Jun 30, 2004
16,627
2,024
126
My own very old laptop only has two slots for SO-DIMM. You say you "have to add 4GB." If this means you have slots available, I'd say to find at least RAM of same manufacture even if not the same "model" which have identical specs, or which have SPD specs which overlap the ones you have.

If you're simply going to replace a 2x-kit with a 2x-kit offering double the RAM capacity, then match the RAM to the compatibility list for that laptop.

I've been able to put two different models (same manufacture) -- DDR2-900 and DDR2-1000 -- in the same desktop; the easiest configuration for them without overclocking is DDR2-800 and the same latency settings. Not something I was ever eager to do, however, but it worked fine.

I would be more precise and demanding in choosing RAM for a laptop.

Incidentally. given the limited laptop BIOS that I have, I can't tweak it to match a RAM-speed spec. It was designed to run the SO-DIMMs at DDR2-667 -- period -- the end. But the Crucial configurator recommendation for replacement RAM on that laptop was for DDR2-800. And when I installed them, they ran at DDR2-667. Nothing I can do about that. It works fine; I quadrupled the amount of RAM in the system; the system benefits for greater RAM capacity.
 

mikeymikec

Lifer
May 19, 2011
21,005
16,257
136
I've had mismatched RAM run fine in dual channel probably about 100 more times than actually matching RAM in dual channel.

Virtually all laptops only have two RAM slots in my experience.
 

bryanl

Golden Member
Oct 15, 2006
1,157
8
81
Here's the specs of the RAM I've got,
11-11-11-28 latency
1.5 Volt
204 pins
1600 MHz

So far I've found 2 RAM sticks I like, and both of them have the same speed and voltage, but differ in latency.

One has a latency of 11-11-11-30 and the other has 9-9-9-24. Which of these should I go for ? Will it be able to work smoothly with the other RAM I've got ?

Or should I play safe and buy the RAM that has the same latency figures as mine.
.
The 9-9-9-24 spec is not honest for 1600 MHz RAM because no 1600 MHz chips are that fast. The 11-11-11-30 spec may be honest, depending on whether or not the chips are actually 1600 MHz, and often 1600 MHz RAM sticks contain 1333 MHz chips.
 

vbcda

Junior Member
Nov 14, 2014
6
0
0
The 9-9-9-24 spec is not honest for 1600 MHz RAM because no 1600 MHz chips are that fast. The 11-11-11-30 spec may be honest, depending on whether or not the chips are actually 1600 MHz, and often 1600 MHz RAM sticks contain 1333 MHz chips.

I'll be honest with you bryanl, I don't know much about RAM specs. I was advised by a pal of mine to get RAM with identical specs and that's what I've been searching for.

I've actually found one with identical speed, voltage and latency figures and have been contemplating ordering it. What do you think ? Should I go for it ?