ram bandwidth and latency

[CmdrJeffSinclair]

At what point does RAM rated at ultra frequencies become less effective than low latency RAM of lower frequencies (if ever)?

For example, will ddr3@1866MHz/CL10 be more effective at day-to-day tasks than ddr4@3200MHz/CL16? Or will the higher bandwidth always be more effective (but simply at diminished returns)?

I've read 2o articles which all seem to say something along the lines of needing a balance between bandwidth and CL.

But will high frequency RAM ever become "less" effective at daily tasks or will it always be better despite ever-rising CL?

Keep in mind I am comparing ddr4 to ddr3, assuming it matters yet

 

[thently]

The reason its not something allot of people look into as it doesnt matter.. I have run ddr3 at cas 14 2400 and cas 9 at 1800 I did not notice any diffrence.. Testing the 2400 gt better synthetic numbers so i guess it is better but at the same CPU speed I bet almost no one would know the diffrence between a computer running 1600 vs 3200.. There might be very specific apps that can do something with faster ram but we are at a point where ram is not really what is slowing us down. It might be in the future with 8-16 cores but right now its not noticeable.

Thent

 

[CmdrJeffSinclair]

The reason its not something allot of people look into as it doesnt matter.. I have run ddr3 at cas 14 2400 and cas 9 at 1800 I did not notice any diffrence.. Testing the 2400 gt better synthetic numbers so i guess it is better but at the same CPU speed I bet almost no one would know the diffrence between a computer running 1600 vs 3200.. There might be very specific apps that can do something with faster ram but we are at a point where ram is not really what is slowing us down. It might be in the future with 8-16 cores but right now its not noticeable.

Thent

You mentioned it might be effective with 8-16 cores computers? What about mine? It's the haswell 8 core 16 thread beasty
SPECS:
CPU: Intel Core i7-5960X 8 cores, 16 threads @3GHz (will OC to 4GHz if needed)
COOLER: Cooler Master Nepton 280L (54~122.5 CFM)
MOBO: Asus Deluxe X99
RAM: 16GB DDR4 G-Skill Ripjaws @3200MHz CL16
GPU: 4GB Sapphire Radeon R9 290X Vapor X Tri X
SSD: 1TB Samsung EVO 850 PRO as main drive
HDD: 1TB Western Digital VelociRaptor @10,000RPM w/ 64MB Cache as a backup drive
PSU: EVGA SuperNOVA G2 1300W

 

[thently]

Touche LOL You will most likely not notice much for ram speed I would not lower the cas spec much below what it is rated for or at all. If you are looking for rock solid stable, buy the best ram you can afford Lowest cas highest speed put it in and forget about it. Nice machine by the way

Thent

 

[sportsfanboy]

Honestly, for normal day to day tasks and gaming, higher speed ram, and lower CL isn't needed. You'll notice it mainly in benchmarks only, unless you video edit or do some pro software tasks that are ram dependent.

 

[CmdrJeffSinclair]

Touche LOL You will most likely not notice much for ram speed I would not lower the cas spec much below what it is rated for or at all. If you are looking for rock solid stable, buy the best ram you can afford Lowest cas highest speed put it in and forget about it. Nice machine by the way

Thent

Nice, haha. Well my machine cost me $4.500, so I can't help but want to make it perfect. Will tightening the timings lower the life of my computer? Will lowering the cas (or trying to) by 2-3 points shorten the life of any of the parts on my PC? If so, I'd never touch any of it. (keeping in mind ddr4 is 1.2v standard over 1.65v for ddr3 gaming RAM, a massive decrease in power at the cost of 48 more pins)

My pc is a next gen gaming server but it is also my own personal computer which makes the loads and usage all the more intensive. I use it to host games *while* I play with friends with a dual monitor setup (hence the beefy GPU) and often times I will be zipping, defragging or scanning while I do these things, so the level of performance I expect is as unreal as it is surreal when you think about it. Chances are pretty high I will benefit from any performance increases relating to CPU and RAM when I host 8-16 player matches on my PC (while I'm also playing with them) and with VM's

I already know overclocking a CPU can shorten its lifespan even with proper cooling, but RAM I'm new to. I'm not looking for bleeding edge tightening that will require 50 restarts, voltage changes and 100 memtests to make sure stability is sane. I mean I'd lower the clocks on tCL-tRCD-tRP-tRAS like 2-3 points one at a time and if it passes memtest86+ then that's it. As soon as any errors creep in I go back up to the last stable clock and leave it alone forever unless firmware comes out (x99 chipsets and ddr4 are constantly updating).

I spent my money on this computer acknowledging the fact that I'm incredibly impatient and overly enthusiastic...a very expensive combination of personal traits in the computer world!

I look forward to everyone's input regarding the RAM questions I posed above xD

 

[sportsfanboy]

Most good ram comes with a life time warranty. Lowering cas latency won't shorten the life span if you keep the ram voltage withing specs. nor will overclocking the cpu if within specs. I have always overclocked and never have I killed a computer part in many years. The problem with memory tweaking is the headache of getting it stable.

Lowering the cas L 2-3 for the main 4 timings is a bit much to start off with. If you're running 9-9-9-27 for example, try starting with 8-8-8-24. Or leave the timing stock(make sure the voltage are set properly) and work on higher frequency.

 

[Brunostako]

Many test out there show very few cases where high bandwidth is useful (for example, APUs).

Actually, DDR3 800MHz CL6 is just a bit slower than DDr3 2400 MHz CL11.

 

[CmdrJeffSinclair]

Many test out there show very few cases where high bandwidth is useful (for example, APUs).

Actually, DDR3 800MHz CL6 is just a bit slower than DDr3 2400 MHz CL11.

I can tell you right now what you said is mostly bunk. I could see very easily the difference between 1033MHz and 1866MHz RAM just with zipping and converting videos, let alone hosting online games and hardcore video/photo editing on my quad core. Games won't benefit it since they are GPU dependent, but I run a server with an 8 core 16 thread Haswell and there are tremendous loads across all cores. My PC devours 16GB RAM like it were nothing

As for APU's, that's completely true. Sadly APU's are not up to par yet.
(Awesome AVI btw)

 

[CmdrJeffSinclair]

Most good ram comes with a life time warranty. Lowering cas latency won't shorten the life span if you keep the ram voltage withing specs. nor will overclocking the cpu if within specs. I have always overclocked and never have I killed a computer part in many years. The problem with memory tweaking is the headache of getting it stable.

Lowering the cas L 2-3 for the main 4 timings is a bit much to start off with. If you're running 9-9-9-27 for example, try starting with 8-8-8-24. Or leave the timing stock(make sure the voltage are set properly) and work on higher frequency.

Nice, well right now the cas is 16-16-16-36
G.SKILL Ripjaws 4 series ddr4

I noticed that the other G.Skill dd4 modules above and below 3200MHz still have the same timings...does this mean anything? Is the RAM pre-overclocked or something?

 

[sportsfanboy]

I would try for lower cas latency on ddr4 to start. If you get it stable, then you may or may not be able to raise the frequency after.

Ram companies bin their ram chips just like cpu manufacturers do. That means, not all ram will handle the same cas latency given the same voltage. The ram chips that are higher binned will get lower latency/higher frequency, and a higher price tag.

 

[Brunostako]

Many test out there show very few cases where high bandwidth is useful (for example, APUs).

Actually, DDR3 800MHz CL6 is just a bit slower than DDr3 2400 MHz CL11.

I can tell you right now what you said is mostly bunk. I could see very easily the difference between 1033MHz and 1866MHz RAM just with zipping and converting videos, let alone hosting online games and hardcore video/photo editing on my quad core. Games won't benefit it since they are GPU dependent, but I run a server with an 8 core 16 thread Haswell and there are tremendous loads across all cores. My PC devours 16GB RAM like it were nothing

As for APU's, that's completely true. Sadly APU's are not up to par yet.
(Awesome AVI btw)

Actually, compressing data is one of the things that scale in performance with the bandwidth.

But, other than that, haven't seen any difference. From the tests i've seen, the increase in performance is about 10% at much from 800 to 2400, even on video encoding. It gain more performance with more memory than high bandwidth.

That's what i've seen.

And on Linus Tech Tips, they made a video about DDR3 vs DDR4 and there was almost no benefit. And they also have a video about DDR3 bandwidth performance.

 

[sportsfanboy]

that's higher speed ddr3 vs ddr4... In pro apps, there's absolutely a difference in say ddr3 1333 to ddr3 2666/ first gen ddr4.

If he is just gaming and using firefox i would say you're correct, but not in pro apps that love fast ram. I dabled years ago in a program called CCE. It's a pro video rendering application. That was way back when ddr2 1066 was fast ram. And I can tell you even then, there was a difference in render time going from ddr2 800 to 1066

 

[CmdrJeffSinclair]

that's higher speed ddr3 vs ddr4... In pro apps, there's absolutely a difference in say ddr3 1333 to ddr3 2666/ first gen ddr4.

If he is just gaming and using firefox i would say you're correct, but not in pro apps that love fast ram. I dabled years ago in a program called CCE. It's a pro video rendering application. That was way back when ddr2 1066 was fast ram. And I can tell you even then, there was a difference in render time going from ddr2 800 to 1066

I don't think Brunostako even read any of the previous posts we all made. I wasn't even asking for opinions on the worth of RAM, only if it was safe and what to expect.

I appreciate everyone's input. This wasn't meant to be a discussion on what RAM is better though, only about safe timings on high bandwidth ram. I think it has been answered sufficiently though

 

[sportsfanboy]

Yeah man... your ram should have a life time warranty. That said you don't want to kill them as you need your computer. Worst case you do an rma and get new stuff, maybe even a free sticker,lol.

I'm not sure what the safe voltage ceiling is on DDR4 since it's so new. Typically, a bump of .05 is more than safe and can provide some overclocking headroom. I would see what it can do on stock volts first. A lot of it might depend on how strong the memory controller is, you'll just have to tinker around.

 

[CmdrJeffSinclair]

Yeah man... your ram should have a life time warranty. That said you don't want to kill them as you need your computer. Worst case you do an rma and get new stuff, maybe even a free sticker,lol.

I'm not sure what the safe voltage ceiling is on DDR4 since it's so new. Typically, a bump of .05 is more than safe and can provide some overclocking headroom. I would see what it can do on stock volts first. A lot of it might depend on how strong the memory controller is, you'll just have to tinker around.

Hey that was some really helpful information. 0.05v addition would be a good place to start. I think what I'll do is get the memory latencies lowered until I see the first errors, then increase the voltage by 0.05v as you said. If it doesn't help, I'll go back to default voltage and use the previous timings that were stable and call it a day. Is that a safe plan?

 

[sportsfanboy]

Yeah that should be perfectly fine/good plan IMO. That voltage bump I suggested is very safe. You might find that once you learn more about your memory, it is probably safe all the way up to 1.4 or more, with decent cooling. I just don't like telling people voltage values that are safe until I'm 100 percent sure.

good luck