So I did a live test on two laptops.
The conclusion is that RAM upgrades can make a significant improvement to latency (reducing it) and are well worth doing.
A few years back, I had used RAM upgrades to a couple of Toshiba (Windows XP) laptops (now defunct), taking them from the standard 512Mb or 1Gb up to 3 or 4Gb. The difference in "feel" was quite impressive. It felt much faster on most large applications, though I had no easy way of measuring this.
A couple of months back, I helped out some neighbours whose Asus (Windows Vista) laptop had been hijacked by a trojan virus. After I had restored it to normal, I thought it was a bit slow, and swapped-in 3Gb of DDR2 RAM from a defunct Toshiba. It seemed much better.
In fact, the transformation was impressive, and the owners were really pleased with the result.
I had purchased my HP ENVY 14 laptop over a year ago, and my daughter's (Lily's) DELL Inspiron laptop about 8 months ago. Looking at laptop DDR3 4Gb RAM card prices, I noticed they were affordable at about NZ$50 each. So I decided to upgrade the two laptops and measure the resulting performance changes.
Currently, laptops seem to come with only two slots for DDR3 RAM.
The HP had 1x4Gb card only, with the other slot empty.
The DELL had 2x2Gb cards - one in each slot.
- I put one 4Gb card into the empty slot, giving 8Gb in total, and then ran the standard Windows Experience Index performance assessment tool.
- I took out one of the DELL's (2Gb) cards, and replaced it with a 4Gb card, giving 6Gb in total, and then ran the standard Windows Experience Index performance assessment tool.
- Then I took out the remaining one of the DELL's 2Gb cards and replaced it with a 4Gb card, giving 8Gb in total, and then ran the standard WEI performance assessment tool again.
From the user's perspective on the HP, I noticed significantly reduced latency in almost any program being run, and especially in MS OneNote, Firefox, Chrome/Chromium, InfoSelect, and some xplorer¬≤ functionality.
From the user's perspective on the DELL, Lily noticed delays being significantly reduced in loading/closing SIMS3 games and in other functionality in SIMS3 and SIMS Medieval, and in online games and Firefox. She said "It was all much faster".
The Windows Experience Index performance assessment results help to explain this, as below: