Noob Question: How does faster ram make your system faster?

[donanderson]

What I mean is, does faster ram just mean that it can pull data from the hdd faster or can it actually make your applications run faster once everything is loaded to the memory?

[ontoptherock]

it doesnt just depend on the speeds, but the timings as well. a fast ram with loose timings isnt going to make your rig necessarily any faster. its possibly a slower clocked ram with tight timings could make it faster than a ram that is clocked higher. like DDR3 ram clocked at 1600 with a CL9 isnt going to be faster than ram at 1333 with a CL of 5 or 6. correct me if i am wrong anyone, but that is my understanding of it. Can't just look at the speeds.

[Bandrew]

well, your hard drive is tons slower than any ram on the market, so you won't see any performance increase from the hard drive to the ram. Most of the time you won't see any real world difference when going from slower to faster ram.

[ebarone]

The RAM is where data is stored for use by the processor... the processor has a couple levels of cache, but they're pretty small and cant contain everything the processor will be using. Remember, your computer runs tons of stuff all at once. So the RAM is a big repository of data that the processor will need to access at a moments notice. When your games show a loading screen, thats the system bringing game data from the HDD to the RAM so it can be readily and speedily accessed by the processor, rather than waiting for a slow HDD to relay data. When you speed up your RAM, either by timings or by actual clockspeed, you theoretically decrease the time it takes for the RAM and the processor to communicate back and forth. Obviously theres a ton of factors that go into it, but in general terms thats whats going on.

 

In specific reference to your question, it doesnt increase the transfer rate between HDD and RAM, the HDD is many many many many times slower than the RAM so the system will be always waiting on that piece of the puzzle, not your memory. It does mean, however, that your applications will run faster. The thing about that though is... you probably wont notice. In the same vein that you wouldnt notice increasing your processor speed by 2MHz, you wont notice anything by going from CL9 to CL8 for example... yea its faster but its not "real world" faster. I hope that answered your questions =)

[wevsspot]

Great explanation by ebarone. But I'll add just two things;

RAM clocked at higher speeds has more bandwidth

RAM clocked at tighter timings has lower latency

 

ontoptherock also added an interesting but true observation - sometimes settling for less bandwidth and tighter timings does improve overall system performance and how "snappy" your rig feels. this was especially true on the nf3 and nf4 chipset boards. intel socket 775/1156/1366 boards don't seem to mind having higher latency memory and really like the extra bandwidth. to some extent the exact opposite was true on the last generation amd cpus/nf based systems.

[ebarone]

IDK what system the OP has, but I just put together a new i7 system and will be tinkering with it soon... I remember when I was OC'ing the system in my signature, a timing of the DDR2 called tRD, or Performance Level, was the one timing that made my system noticeably faster. Is that still true for DDR3 memory? If so then whatever system the OP has could probably stand to benefit a lot from tightening that timing.

[wevsspot]

Performance Level (tRD or some variation of that depending on your board/bios) is kind of tricky on the socket 1366 platform. Many default BIOS settings have it set very tight and that seems to cause problems. My best suggestion is to go right in and set it at 52 -60 from the start. I haven't noticed any significant performance improvements from having it lower, but it can definitely cause stability problems if it is set too low.

[ebarone]

52-60?? In my DDR2 system it was 7...

[donanderson]

Awesome, thank you for the explanations. Nobody else has been able to explain it so well.