Notebook Memory -- Mix & Match Speeds?

[wpcoe]

My Acer notebook computer has two RAM slots, and came installed with 2 x 512MB PC4300 SO-DIMMs. (The FSB is 533Mhz.) I replaced one of the 512MB SO-DIMMS with a 1GB SO-DIMM, and now am considering replacing the other one. The max RAM capacity of the mobo is 2GB.

The problem is, the shops around here (Pattaya) only seem to have 667Mhz SO-DIMMS. I know (or at least *think*) that a 667Mhz SO-DIMM will be backwardly compatible and operate at 533Mhz. However, what I'm not at all sure about is if I can have two SO-DIMMS of different ratings: 1 @ 533Mhz and 1 @ 667Mhz operating side by side. Would that be a problem?

The 667Mhz, 1GB SO-DIMM is definitely affordable: B700 ~ B750 (US$23-25).

[dave_boo]

Your 667 Mhz will drop down to 533. Not that you'd most likely know the difference!

[Guest Reimar]

If you "mix" the memory, you should a little aware about the CL (Cas Latency)! Use the same CL on both memory banks. Keep in mind, as lower the CL as better it is, for example if your existing Memory banks is CL3 you should buy a new one with CL3 as well and not CL 4 or 5.

Fact is, if you existing memory bank is 1 GB 667 with CL4 and you place a new one 1 GB 667 with CL5, the speed reduced a bit and the existing one with CL4 will be "downgraded" to CL5!

I was change in my Acer 5593 the memory from 1 GB 667 CL5 (2 pcs.= 2 GB) to 1 GB 667 CL3 (2 pcs.= 2 GB) which gave me a quite big improvement in speed, which can bee seen a first in the startup time: half then before! And I do not use any Kingston or Kingston related memory like Hynix, Kingmax pp., but if possible Apacer.

But that's my experiences over the years for my business use and my private use as well.

Cheers.

[CobraSnakeNecktie]

My Acer notebook computer has two RAM slots, and came installed with 2 x 512MB PC4300 SO-DIMMs. (The FSB is 533Mhz.) I replaced one of the 512MB SO-DIMMS with a 1GB SO-DIMM, and now am considering replacing the other one. The max RAM capacity of the mobo is 2GB.

The problem is, the shops around here (Pattaya) only seem to have 667Mhz SO-DIMMS. I know (or at least *think*) that a 667Mhz SO-DIMM will be backwardly compatible and operate at 533Mhz. However, what I'm not at all sure about is if I can have two SO-DIMMS of different ratings: 1 @ 533Mhz and 1 @ 667Mhz operating side by side. Would that be a problem?

The 667Mhz, 1GB SO-DIMM is definitely affordable: B700 ~ B750 (US$23-25).

Does anyone know where to get RAM for my Apple MacBook Pro 2 Ghz? its DDR2 667 mhz 200 pin and I am looking for single 2 GB simm. Does anyone know a good source that is not a ripoff?

I can get it for $60 on Ebay but then it costs me another $25 to have it shipped from the US. The overpriced Mac store up here in Chiang Mai wants like $220. hel_l to the no will I pay that. Must be some better sources out there. Any leads?

[Guest Reimar]

My Acer notebook computer has two RAM slots, and came installed with 2 x 512MB PC4300 SO-DIMMs. (The FSB is 533Mhz.) I replaced one of the 512MB SO-DIMMS with a 1GB SO-DIMM, and now am considering replacing the other one. The max RAM capacity of the mobo is 2GB.

The problem is, the shops around here (Pattaya) only seem to have 667Mhz SO-DIMMS. I know (or at least *think*) that a 667Mhz SO-DIMM will be backwardly compatible and operate at 533Mhz. However, what I'm not at all sure about is if I can have two SO-DIMMS of different ratings: 1 @ 533Mhz and 1 @ 667Mhz operating side by side. Would that be a problem?

The 667Mhz, 1GB SO-DIMM is definitely affordable: B700 ~ B750 (US$23-25).

Does anyone know where to get RAM for my Apple MacBook Pro 2 Ghz? its DDR2 667 mhz 200 pin and I am looking for single 2 GB simm. Does anyone know a good source that is not a ripoff?

I can get it for $60 on Ebay but then it costs me another $25 to have it shipped from the US. The overpriced Mac store up here in Chiang Mai wants like $220. hel_l to the no will I pay that. Must be some better sources out there. Any leads?

May you check with http://www.shop4thai.com or http://www.jib.co.th

In Bangkok no problems to get.

Cheers.

[wpcoe]

If you "mix" the memory, you should a little aware about the CL (Cas Latency)! Use the same CL on both memory banks. Keep in mind, as lower the CL as better it is, for example if your existing Memory banks is CL3 you should buy a new one with CL3 as well and not CL 4 or 5.

Fact is, if you existing memory bank is 1 GB 667 with CL4 and you place a new one 1 GB 667 with CL5, the speed reduced a bit and the existing one with CL4 will be "downgraded" to CL5!

I was change in my Acer 5593 the memory from 1 GB 667 CL5 (2 pcs.= 2 GB) to 1 GB 667 CL3 (2 pcs.= 2 GB) which gave me a quite big improvement in speed, which can bee seen a first in the startup time: half then before! And I do not use any Kingston or Kingston related memory like Hynix, Kingmax pp., but if possible Apacer.

But that's my experiences over the years for my business use and my private use as well.

Cheers.

Thanks for reminding me to pay attention to the CL. I didn't realize the "upgrade" from CL5 to CL3 (as in your case) would amount in a noticeable speed boost. Need to keep that in mind.

I'm going to take my notebook down to the shop "one of these days" (I'm not in any hurry) as they said they will install it, and I don't pay if it doesn't work. If it does work, I'm hoping they'll indulge me and let me run CPU-Z to check the latencies of the two SO-DIMMS. It might result in an upgrade to a pricier piece of RAM if the cheap one (B700) has too low of a CL rating.