Question:
dual channel vs more memory
I currently have 512 mb on my laptop and wanting to put another 512 mb...if I wanted dual channel I probably would have to get the ram from manufacter that would cost around $70+...it's almost same as buying 1 gb ram if buying online. so which is better, 1gb dual channel or 1.5gb without dual channel?
Answer:
Re: dual channel vs more memory
1.5GB. The extra bandwidth provided by dual channel is rarely used up. But Windows will be able to make use of the extra memory any day. Also for dual channel you can use any 512MB stick which has the same specifications as the current RAM. It does not need to be from the same manufacturer.
Answer:
Re: dual channel vs more memory
in cpu-z it shows my memory timing 4-4-4-12
I found this one at 4-4-4-11...would it work?
kinda hard to find right timing most usually says timing at 4 and nothing else...
Answer:
Re: dual channel vs more memory
It should. If you add a faster memory to a slower one it should run at the same speed as the slower memory. If you add that one it should make it run at 4-4-4-12.
Answer:
Re: dual channel vs more memory
ah ok i got it, thanks
Answer:
Re: dual channel vs more memory
Just wanted to point out that, if you run 2 banks of memory that are not identical you will no longer get dual channel. indentical means size and all timings. so both 512MB, but slightly different timings will work, but will not be dual channel. miner is right, that memory op freq will clock to the slower chip, but the latencies will not adjust.
At least that is my understanding.
[Correction] - Only size/capacity has to be identical to get dual channel. memory chip technology can be different. So the latencies will not adjust, but the system will operate in dual channel mode, where addresses ping-pong between the two channels. On further thought this makes sense since no two chips, matched or not, are going to perfectly identical in timings, etc.
Answer:
Re: dual channel vs more memory
really cant get what you mean...
lets assume i bought the 4-4-4-11 and i have 4-4-4-12
so the one with the 11 wont change to 12
but it will still run dual mode?
I still haven't made my mind which to buy hehe..because I always prefer buying online because its cheap...512mb 533mhz in store cost prob almost as much as a 1gb 533mhz online...
but if buying a 512 mb 533 online will be cheaper...but will run a risk of not running dual channel and really don't like to online return/refund...
Answer:
Re: dual channel vs more memory
I'd just get more memory - dual channel does almost nothing in terms of performance.
AnandTech did a test to see if it made any difference in speed in OS X and Windows, and it didn't make any. Click here for the review.
Answer:
Re: dual channel vs more memory
really cant get what you mean...
lets assume i bought the 4-4-4-11 and i have 4-4-4-12
so the one with the 11 wont change to 12
but it will still run dual mode?
I still haven't made my mind which to buy hehe..because I always prefer buying online because its cheap...512mb 533mhz in store cost prob almost as much as a 1gb 533mhz online...
but if buying a 512 mb 533 online will be cheaper...but will run a risk of not running dual channel and really don't like to online return/refund...
I'll start with the advice first and the explanation second.
Advice: If you go with 1GB min, then get 2 512MB chips. In your case I'd just buy another 533Mhz 512MB chip, it's the cheapest route and you'll never notice the difference with 667. For most normal uses, you probably wouldn't notice the difference between 1GB and 1.5GB. (See Tom's Hardware, they have a nice article on "how much memory you really need") This article shows a negligible performance gain for memory increases in the 1-2GB range. 512MB to 1GB is a big gain. That being said, a stick of 1GB 533Mhz is only going to cost you $80 or so. If you keep your original 512MB, don't bother getting a 667chip, stick with 533.
******The explanation on Dual Channel modes*********
Been thru this pretty extensively today in another thread, so here's the short version.
Dual Channel simply requires both slots be occupied, size, time, freq do not have to match.
However, the Dual Channel benefit that everyone implies you will get only occurs when the size of the memory in each channel is identical. I know this is true for the Intel 945GM/PM chipset. In Symmetric mode (equal size in both channels) addresses ping-pong between channels, so you effectively get overlapping (simultaneous) access on each channel; that is, the system will initiate a read on the other channel before the first one is done, which is why timings don't have to match, just size.
If you have two different size chips in the 2 channels, addresses are dealt with one chip at a time until it maxes out, then it goes to the next chip. For example, if your memory was full and you were reading it out, you would read out the first chip, then read out the second. In Symmetric dual channel, you'd read them out in an overlapping manner, virtually simultaneously.
I'm sure I muddied the waters even more. buy a 1GB stick of 533 and go for 1.5GB. good luck.
Answer:
Re: dual channel vs more memory
Here's another question to keep things confusing:
I just ordered a Toshiba Satellite M100 with the minimum memory (1x256MB, 533). I plan on buying a single 1GB stick of memory (newegg has 1x1GB/667 for $90). Now, should I simply add the 1 GB in addition to the 256 to use 1.25GB total (@ 533)? Or, should I remove the 256 when I upgrade, so as to keep the memory running at the higher 667?
Thanks!