RAM: Latency vs Speed???

[webJockey]

RAM: Latency vs Speed???

Hi guys, just confused in selecting right ram for my rig. With my budget I can only choose one thing. Either better latency or better speed. Can’t afford both. No plan of OCing ram at thus stage

So here are the choices:

CORSAIR XMS3 6GB (3 x 2GB) DDR3 1333. Cas Latency: 7. Timing: 7-7-7-20. Voltage: 1.5v Model:TR3X6G1333C7 G

CORSAIR XMS3 6GB (3 x 2GB) DDR3 1600. Cas Latency: 8. Timing: 8-8-8-24. Voltage: 1.65v Model:TR3X6G1600C8 G

I do HD video editing. NO GAMING AT ALL. Which one will perform better. Any feedback will be highly appreciated.

Thanks in advance

System Configuration:
Processor: i7 920 (OCed 3.8Ghz)
Mobo: Asus P6T
GPU: ASUS Radeon HD 4670
PSU: Corsair 520w Modular HX520

 

[Fourstaff]

How about better latency and then oc the speed? If you dont game, then both of them is pretty the same, my vote goes to better speed.

 

[jjFarking]

Not sure you'd notice the difference actually..
The other thing is, those Corsair's happily run at lower latencies with increased voltages. As in your example, running the 1600 modules @ 1.8v should allow you to run them at 7-7-7-20 anyways

 

[webJockey]

Not sure you'd notice the difference actually..
The other thing is, those Corsair's happily run at lower latencies with increased voltages. As in your example, running the 1600 modules @ 1.8v should allow you to run them at 7-7-7-20 anyways

I have read somewhere that voltage should not be more than 1.65. otherwise i may burn the things

 

[douglatins]

RAM: Latency vs Speed???

Hi guys, just confused in selecting right ram for my rig. With my budget I can only choose one thing. Either better latency or better speed. Can’t afford both.

So here are the choices:

CORSAIR XMS3 6GB (3 x 2GB) DDR3 1333. Cas Latency: 7. Timing: 7-7-7-20. Voltage: 1.5v Model:TR3X6G1333C7 G

CORSAIR XMS3 6GB (3 x 2GB) DDR3 1600. Cas Latency: 8. Timing: 8-8-8-24. Voltage: 1.65v Model:TR3X6G1600C8 G

I do HD video editing. NO GAMING AT ALL. Which one will perform better. Any feedback will be highly appreciated.

Thanks in advance

System Configuration:
Processor: i7 920 (OCed 3.8Ghz)
Mobo: Asus P6T
GPU: ASUS Radeon HD 4670
PSU: Corsair 520w Modular HX520

OMG OMG OMG

 

[jjFarking]

It does obviously depend on the specific models. That said, however, Corsair is one of those companies that test their RAM at higher voltages than the release models - ensures durability & quality control is second to none (well, kind of).

 

[slyfox2151]

Best not to go over 1.65 with an I7,

You should grab the 1333mhz 7-7-7-20 @ 1.5v

Up the volts to 1.65 and see if they can run at 1600mhz 7-7-7-20

 

[DrPepper]

Higher speed even with the higher latency is faster.

 

[jjFarking]

Best not to go over 1.65 with an I7,

You should grab the 1333mhz 7-7-7-20 @ 1.5v

Up the volts to 1.65 and see if they can run at 1600mhz 7-7-7-20

Agreed. The lower the voltage you can get the RAM stable at with lower latency, the better it is of course.
I merely mentioned the fact that Corsair is not afraid of higher voltages

 

[jjFarking]

Higher speed even with the higher latency is faster.

Don't you mean lower latency?

 

[slyfox2151]

Higher speed even with the higher latency is faster.

Pritty sure id take that with a grain or 2 of salt...




lower ram timing's with lower speed is faster in WINRAR.

 

[DrPepper]

Don't you mean lower latency?

Pritty sure id take that with a grain or 2 of salt...




lower ram timing's with lower speed is faster in WINRAR.

Check the benchmarks in my sig. 1600 at CL8 is faster than 1333 at CL7

 

[slyfox2151]

the problem is not if the ram can take the voltage but the CPU.

it is stated by intel that anything over 1.65 can damage the cpu .. IIRC

 

[slyfox2151]

Check the benchmarks in my sig. 1600 at CL8 is faster than 1333 at CL7

where is the WINRAR benchmark? i couldnt find it.

 

[jjFarking]

Interesting article.
What interests me there is the latency you got. Clearly the lower latency RAM should have scored lower, but didn't. That indicates an issue with either that particular RAM, or the way the mobo/CPU handles it.
There's no way on this green earth that 7-7-7-20 would have a greater latency than 9-9-9-24 timings.
Throughput changes with the increase of RAM speed, but access speed is critical in other areas.
Convince yourself with wPrime.
Keep the speed the same, but lower the latency and see just how much that's affected by the change..

EDIT:
I have two older results
Latency 9-9-9-24 (1333MHz):

Latency 7-7-7-20 (1333MHz):

 

[DrPepper]

where is the WINRAR benchmark? i couldnt find it.

Damn never noticed it was missing.

Interesting article.
What interests me there is the latency you got. Clearly the lower latency RAM should have scored lower, but didn't. That indicates an issue with either that particular RAM, or the way the mobo/CPU handles it.
There's no way on this green earth that 7-7-7-20 would have a greater latency than 9-9-9-24 timings.
Throughput changes with the increase of RAM speed, but access speed is critical in other areas.
Convince yourself with wPrime.
Keep the speed the same, but lower the latency and see just how much that's affected by the change..

EDIT:
I have two older results
Latency 9-9-9-24 (1333MHz):
http://img64.imageshack.us/img64/7706/wprime3913.jpg
Latency 7-7-7-20 (1333MHz):
http://img340.imageshack.us/img340/4639/wprime3913reducedlatenc.jpg

Actually that's how it works the faster speed actually reduces latency, despite higher timings.

 

[jjFarking]

Right.
So my old DDR1 RAM @ 400MHz had a latency of 42ms with 2-2-2-5 timings, whereas my 1333MHz DDR3 RAM has a latency of 52.7ms # 9-9-9-24 timings, but the DDR3 has reduced latency nonetheless?
How does that work?
Latency dictates access speed. MHz dictates throughput per clock cycle.
Increased speed by no means decreases latency..

 

[DrPepper]

Right.
So my old DDR1 RAM @ 400MHz had a latency of 42ms with 2-2-2-5 timings, whereas my 1333MHz DDR3 RAM has a latency of 52.7ms # 9-9-9-24 timings, but the DDR3 has reduced latency nonetheless?
How does that work?
Latency dictates access speed. MHz dictates throughput per clock cycle.
Increased speed by no means decreases latency..

Increased speed does = less latency. That's what all the test's show. If you stick your ram at 1600mhz 8-8-8-24 against your 1333mhz at CL7 the latency will be lower for the 1600mhz. I've ran those test alot of times and I always get the same results even on diffent computers.

Why have you got your 1333mhz ram at CL9 ? That's rediculously high for that speed. I run CL9 for 1866mhz. Explains your high latency.

 

[jjFarking]

Everest's Latency Test - Basic results included in the program:

Notice a trend?
One thing to consider also is the command rate. Obviously, CR1 is better than CR2

 

[jjFarking]

Why have you got your 1333mhz ram at CL9 ? That's rediculously high for that speed. I run CL9 for 1866mhz. Explains your high latency.

That's the default latency of this RAM.. Sucks, I know, that's why I decreased it

 

[DrPepper]

Okay here's my results

If I go to 1833mhz and oc my cpu I can get the top spot on this chart.

 

[jjFarking]

Hmm.. Why are you running CR2?
No wonder your latencies can be relaxed so much

 

[DrPepper]

Hmm.. Why are you running CR2?
No wonder your latencies can be relaxed so much

Yeah I get the best results using CR2.

 

[jjFarking]

Is there a chance you can OC your RAM only & see what the latency difference is?
Increased CPU speed will affect the latency somewhat as well, so to test the theory, only the RAM should run faster..

 

[webJockey]

Is there a chance you can OC your RAM only & see what the latency difference is?
Increased CPU speed will affect the latency somewhat as well, so to test the theory, only the RAM should run faster..

I dont wanna touch ram at this stage.