Although RAM will have some impact on render speed, generally speaking faster RAM isn't going to make a very appreciable difference in render times. Perhaps a few seconds in a 3-5 minute render, but not much more. Amounts of memory below 1GB would have a greater effect, as of course would the CPU.
Setting up benchmark scenes is a tricky thing. Ideally you want as many people as possible to run it to get the widest basis for comparison, but many people are impatient, so a quick benchmark is desirable for that reason. On the other hand the faster the benchmark the greater the margin for error, especially when time is being measured in seconds. To illustrate this, think about the difference between a 50 second render and a 100 second render - the 2nd is twice as long. Now let's imagine the impact of starting another program, even a simple document editor or email program, while the render is happening. Let's say it slows down the render for about 10 seconds as the application loads. That's going to have an impact of as much as 10% on overall render time! But now imagine the imapact of that 10 second slowdown on a 1000 second render - it's only a maximum of 1%. So the longer your render, the more such small and usually inevitable CPU spikes are minimized in terms of their effect on the overall render time. In this particular case the render times are fairly short - I would have aimed for something more like 20-30 minutes - so accuracy may be suffering as a result of that. There are also often processes that are difficult or impossible to truly get rid of before rendering - these would include antivirus scanners and other security software. Depending on the configuration of your security systems this may have a significant impact on render time. Finally remember that the results here are reported by individuals and subject to human error and possible embellishment. It's useful to have a wide variety of results from similar machines to get an average, in case someone is misreporting for some reason. Never assume an unusual result is simply someone who knows how to optimize their system; it's more likely an error.
As far as the increased render times, although some changes to the rendering engine were made in this update, you should not be seeing significantly increased render times in most cases. As noted in the change log there were some accuracy improvements in cloud rendering that may result in slightly slower render times, but the numbers being reported here are unexpected. We will certainly look into these potential issues. It may be useful if people continue to report their results here in this thread so we can get a better idea of whether this is affecting everyone the same. We've already seen at least one person saying they can't duplicate the issue.
- Oshyan