Will using 1x4GB and 1x2GB sticks hurt performance?

Isn't it best to use identical RAM in each slot? So wouldn't using 6GB (split as seen in title) possibly cause issues? I could be wrong... but I'm curious.

 

It will hurt dual channel performance (in mostly synthetic benchmarks) - but won't affect anything real world to worry about.

 

Ok good to know.

 

it will hit performance but yeah not noticable.. really but still , your better off with dual channel.. no harm done getting another 4GB stick... its pretty cheap.. always better to have dual channel.

 

As stated above, a single stick won't work in dual channel mode thus sacrafice RAM throughput somewhat. Two different capacity sodimm's however will run in asynchronous dual channel mode on newer laptop's.

If it was me I would always go for two sodimm's, I personally like to stay with the maximum performance I can get out of the hardware.

Probably worth reading the below links.

Will my memory run in dual channel mode if I install a 2GB DDR2 SODIMM and a 1GB DDR2 SODIMM

Dual channel - making the most out of memory performance

 

I second what 247 said.

I would even go as far as installing identical RAM modules instead of just upgrading the existing one to 'sort of' match it.

Not only will you get the maximum performance your system is capable of (because of fully synchronous dual channel mode), but your x64 O/s will use the extra RAM to full advantage too.

Considering the cost of 2GB vs. 4GB modules now, the benefits outweight any savings - as long as your usage will fully utilize the extra RAM.

See also:
Memory Upgrade: Is It Time To Add More RAM? : Introduction

 

Don't worry about it. If you can fully utilize your memory, 6GB async > 4GB sync.

 

I'll be using quite a lot of RAM on virtual machines, so I'm really considering upgrading to 8GB.

 

Forget about dual/single channel. The simple rule you need to follow is that more RAM is always better!

If you have 2GB and want to upgrade and your choice is between 2GB (matched pair) or 4GB then definitely get the 4GB! (if the cost difference doesn't matter). Even if you don't think you will ever "need" 6GB of RAM, Windows certainly will put a good chunk of it to use vs only having 2-4GB. The more RAM you have the more Windows let the belt loose you can say and puts itself in RAM rather than running from the (slower) HDD.

 

If you need more memory, you know you need it. For the rest, cost is usually the main deterring factor and the fact that unused memory is wasted memory. In that case, you'd actually notice a much better result in upgrading the HDD since that's the limiting factor.

 

^ Agree with sgogeta4.

The general rule of thumb is that RAM is about 100 times as fast as a hard disk, so any extra RAM that's used reduces the need to go to the slow disk, and that's where you see the real improvement. Async vs. sync dual-channel is not a particularly big deal, so if the 6gb saves you disk accesses vs. the 4gb then it's worth it.

Before getting more RAM than you have a use for just to get sync dual-channel, see if there's anything else that the money could be more effectively spent on, such as faster storage (fast HDD or SSD). Seeing as you're using a 5400rpm drive, I'd say that upgrading that would be a priority over going from 6 to 8 gb.

 

Ram is always the first thing to upgrade. Especially as he'll be using multiple VM's.

The bare cost of the components is not the issue to consider: it is the total cost of buying the RAM or the HDD, and installing the new part. With RAM it is a five minute process. With the HDD it is closer to a day or two (I only recommend a clean install) that should also be costed out at your $$/HR you normally make.

So, while I too agree with sgogeta4 in general, in this specific instance the RAM upgrade is what will give the biggest performance increase - not the HDD.

For the HDD, I would simply consider trying PerfectDisk as it can very effectively mask most 5400RPM vs. 7200RPM differences.

See:
http://forum.notebookreview.com/har...-c-b-defrag-c-x-defraggler-perfectdisk10.html

 

Thank you very much for perfectdisk10.

I plan on upgrading my RAM AND HDD actually =p Seagate Momentus XT 500GB and 8GB of RAM. Doing it in Jan. or Feb. when prices go even further down for the momentus and hopefully it improves in some way.