Since upgrading from 3GB to 4GB, I've noticed a huge all-around performance improvement on this notebook. It's a Compaq, dual core 2.1GHz P320, running Windows 7 Home Premium 64-bit.

I presume the performance boost is due not only to having 33% more physical memory, but also because the system is now running the memory in dual channel (128-bit) mode, whereas before, it was running only with 64 bit access (maybe a real- world performance delta of 7 - 12%?)

When I removed the single 1GB SODIMM, and added a 2GB SODIMM that matched the one still installed, it went to dual channel, 128-bit bandwidth.

I can run Firefox 4 with 10 tabs open, Urban Terror 4.1, Yahoo Instant Messenger, mIRC 7.13, four Windows 7 gadgets, and Eve Online Incursion all at the same time with ease, and switch among them with no delay, and still end up having around 2GB physical RAM available to play around with, according to Win 7 task manager. I cannot slow this notebook down.

Both cores in the CPU stay around 22% use, temp is around 70° C. About 240 threads, total. The games I'm running are of course single-threaded, but it sure seems like Windows 7 64-bit somehow spreads the load evenly across both cores quite well. In which case, my question is this: does the OS spread the background I/O and kernel processes & threads evenly across both cores, as well? Or does one core get more of the OS & kernel tasks than the other one?

I wonder how this thing would run with the max. 8GB memory installed, and with an AMD N640 or N660 CPU. (2.9 & 3.0 GHz, respectively)

um it would run sick sick sick...just upgraded my dv7-4053cl to x920be from the n620 I also have dual channel 8gb of ram....will have this laptop for a very long time

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It is what it Is!

Very nice AMD quad core there, Boosted. I hope you fun with it!

Actually, I take back what I said about "dual-channel mode", and 128 bit wide memory addressing on my computer.

Even though I have two identical 2GB PC3-10600 sticks installed, and even though they are running in "dual-channel mode", they are *not* running with 128 bit wide addressing, as I just found out. My computer is running the two sticks in "unganged" mode (effectively, one memory stick dedicated to each core), which still uses only 64 bit wide memory addressing . For 128 bit addressing, they'd have to be run in "ganged" mode, but it seems that this addressing scheme would slow things down in most multitasking scenarios, and besides, AMD recommends unganged mode, so I'll take their word for it.

I can't run in "ganged mode" anyway. There's no option to select it in my BIOS setup, or anywhere else.

Just an FYI

Cheers.

is those dual mode done by RAM manufacture or by chipset manufacture?

Neither.

The dual channel mode is strictly a function of the CPU's memory controller ("MMU" - Memory Management Unit"). However, in most cases, the memory sticks must be of the same size and speed for it to work.

nah i dont think same stick size and brand and speed can work too. i ve done with apogeee stick . dual channel mode not aktif yet.

I'm not sure I understand what you're saying, Mimikrix. And what does "aktif" mean?