Ram - Performance and Size vs Dual Channel

I'm relatively new to understanding dual channel ram, and has a couple of questions. I have a toshiba M60 with a P-M 750 and 1X512 MB of PC4200 DDR2 and a 128 mb geforce go 6600. I mostly run low intensity programs such as excel, word, and surfer (surface modelling, mostly 2d), some autocad (no rendering). But I do enjoy playing some games such as half life 2 and doom 3, and find their overall performance good, but that thay they could definitely benefit from more ram. So to give me a performance boost, I was looking to upgrade my ram to 1.5 GB. However, I've recently come to realise that I'm only running in single channel mode (266 Mhz), and that adding a 1GB stick of ram will keep things this way, while adding 512MB will allow me to run in dual channel mode at 533 Mhz.

My question is this - will I notice a better performance gain from having 1.5 GB of single channel 266 Mhz ram or 1 GB of 533 Mhz ram? My instincts and research tell me probably the latter would be better overall, but also that dual channel mode only really helps during CPU intensive activity and less so for general program opening and running - so more for games, but perhaps having 1.5 GB might overall boost performance more. Load times are long, largely due to a SLOW 4200 rpm HD, and I will probably upgrade my to 7200 this xmas, but until then I'd like a small performance boost. All suggestions welcome!

Thanks

Cheffy

P.S. - buying two 1 gb sticks is not really an option, I don't want to spend too much right now.

 

When talking RAM, size is almost always better than speed. Dual-channel offers only a minimal performance boost, while tripling your memory will make you think you computer has decided to love you. Go from a 4200 RPM drive to a 7200 and you will feel like you have a new system.

 

As posted, dual-channel memory does not make much of a difference. More RAM = better.

Having single-channel RAM does not cut your memory speed in half - it is going to run at the at the same frequency either way. The memory your laptop takes is DDR2, so its Double Data Rate speed is 533MHz.

To give a really basic explanation of dual-channel RAM, it means that there are two doors going into the memory through which programs can access stored info, whereas single-channel memory has only one door. Sounds more useful than it is actually is.

Even if you do not have two sticks of the same capacity (ex: 1x 512MB + 1x 1024MB), it will still run in dual-channel mode because the i915 chipset has a feature called asynchronous dual-channel. It does not offer the benefits of running dual-channel with two even capacity sticks, but like I said, it hardly makes a difference anyway. Don't worry about it.

 

It depends on how much memory you actually use. (Yes, I know this is terribly vague and next to useless)

When you "run out of memory", Windows has to use the pagefile, which is roughly a million times slower than RAM. So when this happens, it's Bad News(tm).

The point is that if this happens, the performance penalty will far outweigh the extra 50-100% you might get by using faster RAM.
But if it doesn't happen, the amount of RAM won't make a difference at all, and then those extra 50-100% you might get from faster RAM is all you can get.

It's hard to say though, I run 1GB in dualchannel, and it works fine for most purposes. I rarely have noticeable pagefile usage, so I don't really need more than that at the moment.

However, 1.5GB certainly can't hurt. And typically, notebooks can't really utilize the bandwidth offered by dualchannel in any case. (The CPU just doesn't need that much bandwidth most of the time)

So hard to say. I'd say you would probably be happy with both solutions.

 

Hello all,

Thanks for all the interesting input. I have thought about it and will probably purchase a 1 gb stick for now then, although I'm sure 1 gb ram is certainly enough for now. Besides, later on I can always swap the remaining 512 mb for another 1 gb stick.

I have another question though. I've noticed that some SODIMM sticks are listed as 200 pin, while others as 240 pin. Perhaps it is an error on behalf of the company listing it (e.g. tigerdirect), but are there actually two different types of ddr2 sodimm pc4200? My current stick is a samsung, but will probabl pick up some corsair value select.

 

Make sure you get the 200-pin SODIMMS - 240-pin DDR2 is desktop RAM. If you send us a link to the module you plan on buying, we can tell you whether it will work or not.

 

I would have to agree, 1.5 GB in single channel is much better than 1 GB in dual channel. I would get this RAM:
http://www.newegg.com/Product/Product.asp?Item=N82E16820145593
It will work with your laptop.

 

Guys, can you explain to me why I see so many "benchmarks" and tests where it makes it look like dual-channel gives you faster performance and really makes a good difference? Are these all using older technology or what exactly? Cause it seems like one can find lots of tests that show the "benefits" of dual-channel. I'm not pretending to know or anything, just trying to make sense of what seems like contradictory information.

 

What sort of processors were they testing? Processors like the Pentium M and Core Duo don't really make use of the extra bandwidth afforded by dual-channel memory, although desktop processors like the Pentium 4 certainly can.

 

Quoted for truth. Too many people think simply adding memory makes all applications run instantly faster. Not true. You see no difference unless you actually use up what you already have.

I can run 32 track Protools sessions on my laptop with 1GB. Peak system memory usage while doing this is around ~650 MB. This means that if I increased my memory from 1 GB to 2 GB I will see NO difference because I'm not even using what I have.

Do some of your most intensive tasks then check your task manager's "performance" tab, look under "commit charge". That's your system's peak memory usage since its last restart. If your peak usage is close to or more than your total physical memory, more ram will speed up your machine at times of maximum usage. If you have a peak usage of 600 MB, then 2GB of ram will do nothing for you.

If you are planning on playing the very latest games (not HL2 or Doom 3), you will want more than 1 GB because the latest games will actually use it and you can count on future games using it too.

 

Thanks Chaz, I'll be sure to note 200 pin only! I will probably purchase through a local computer store, they offer the corsair value select for a good price and I like to feed the little guys where I can. They said they can pretty much order whatever I might want.

As for memory usage, work-wise I'll never probably make use of even 1 gb. However, I do like to play games sometimes, and I found that minimising half life two and attempting to open internet explorer actually caused windows to give me an "out of memory" note. Considering my paging file is set to 1500 MB, and I have 512 mb ram, that seems considerable! I removed the crapware that came with my notebook, and minimised all extra programs too!