2GB (2x1GB) vs 2.5GB (1x2GB+1X512MB)

Hi,

Assuming the laptop is a Dell XPS M1330, what would be better to have? 2 slots filled with 1GB sticks or 2 slots, 1 with a 2GB stick and 1 with a 512mb?

I hear a lot about max performance coming from using two of the same sized sticks in each slot but I don't understand it much...which of these configurations would you advise? Will there be a notable difference?

Matt

 

click here for a threadto solve your question

 

long story short, you'll want 2 sticks of the same size and speed. (e.g. 2x1GB DDR2 667 200-pin).

This is called a dual channel configuration and will give you better performance.

If you're doing a lot of 3-D graphics work,CAD, audio/video editing, photoshop, etc...buy a single 2GB stick and then you can always add another later on.

 

Dual-channel memory does not actually make that much of a difference. More RAM = Better. Go for the 1x 2GB stick because then you won't have to worry about replacing that module later. 2GB RAM sticks are actually very cheap these days, check the RAM DEALS thread.

 

Thanks everyone for the advice and links, I will check them out. If budget allows I will go for the 2GB stick as like you say, it will be easier to upgrade to 4gb.

Matt

 

Actually I must disagree. As you can see below, it does make a difference:

 

But there will be more RAM involved with the single channel, and therefore single is the best bet. Anyways, how did single perform better than dual with the Super Pi results?

 

the lower the number in SuperPi the better (SuperPi calculates how long it takes the computer to calculate pi to the millionth digit.)

 

If we were talking about equal amounts of ram, I'd agree. But 2GB in dual channel would not always come out on top against 3GB in single channel (for example). I guess it would depend if the application is more starved for ram or just bandwidth.

 

I attach a could of results which I measured last week using Sisiftware Sandra's memory bandwidth benchmark. The computer was a Samsung Q70 (Intel 965PM chipset). The 2 x 1GB (should be dual channel) is about 5% faster than the 1GB + 512MB (should not be dual channel).

Overall performance benchmarks tend to not demonstrate the benefit of more RAM provided there is enough RAM for the benchmark to run but will show the benefit of faster RAM.

I am a believer that more RAM helps performance more than slighlty faster RAM, but I usually have lots of applications open.

John

 

Yes there is some difference, I wasn't disagreeing with you there. All I was trying to say was that the performance benefit offered by matching sticks was not enough to sacrifice more RAM. From looking at the benchmarks you posted the difference is indeed very small, and I doubt it would be noticeable in real life applications.

 

Thanks for all the replies

Can someone just confirm what memory the M1330 takes? Is it DDR2 PC2-5300? Also does it matter if the frequency is above the 667MHz Dell seems to give us?

For example (not buying it), would this work?
http://cgi.ebay.co.uk/2GB-PC5300-54...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

Matt

 

The M1330 will use standard 200 pin DDR2 SODIMM. The memory you have identified should work fine.

If in doubt, you can use Crucial's memory selector which gives this for the M1330 (you may need to select show all - it defaults to the PC6400 modules). Currently 2 x 1GB is £58.74 while 1 x 2GB is £78.71. Those prices include delivery. Ebuyer is a bit cheaper.

John

 

Thanks a lot John! Why is there such a huge price difference between the 5300 and the 6400? Is there a notable difference?

 

6400 is basically new tech (just started being used in Santa Rosa I think)

 

PC6400 has the potential to run faster.

However, at the moment it seems to run at 667MHz with the Santa Rosa chipset. Look at the benchmark results in this thread.

John

 

A question about dual channel and cpu-z!

My laptop have 1 GB DDR2 667Mhz PC2-4200 RAM. Atleast thats what the sticker on RAM says. But when i run cpu-z it says PC2-4300...???? anyone now why...???

If i want to run dual channel i have to get another 1 GB 667 Mhz DDR2 stick. Does it have to be PC2-4200/4300??? or can i also use PC2-5300...???

I found out that what matters is the latency. My have CL4 and PC2-5300 are normally CL5. Does that make any reallylife difference in everyday use???

PC2-4200/4300 are very rear at the moment. When i found some they are always 512MB sticks.

 

PC4200 and PC4300 are effectively the same. The latter has slightly faster timings. I have never seen dual channel giving a major performance boost to notebook RAM (maybe 5% to 10%). The key thing is to have more RAM.

If you are buying some more RAM get the PC5300. The BIOS will check the RAM timings on boot-up and run it at the same speed as your PC4300 module.

CL means Clock Latency which is the number of timing steps needed for RAM functions. CL=4 @ 533MHz is the same amount of microseconds as CL=5 @ 667Mz.

I hope this clarifies.

John