The truth about DDR latency times.. is there much of a diffrence..

adamknox

adamknox

adamknox

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Hello!
At the moment i have http://www.overclockers.co.uk/showproduct.php?prodid=MY-183-OC&groupid=701&catid=8&subcat=1516 (im 99% sure thats the one i have)
Just out of intrest for gaming is there REALLY that much improvment going from 9-9-9-20 to this

http://www.overclockers.co.uk/showproduct.php?prodid=MY-177-OC&groupid=701&catid=8&subcat=1516

which is 7-7-7-20

or even this

http://www.overclockers.co.uk/showproduct.php?prodid=MY-107-OC&groupid=701&catid=8&subcat=1516

which is 6-5-5-18
Im not talking about improvment of minute sort. I mean as in "WOW THE DIFFRENCE IS AMAZING!" lol

Im pretty sure i could overclock my ram to get faster.. but i have no idea when it comes to overclocking ram lol SO i think paying for it is safer ;)
 
its only a minor difference in load times. More ram = bigger difference than timings etc, and to your FPS it will not make more than a few %.

Generally anything better than "standard" speeds and timings is aimed at overclockers, or at least at people using memory intensice programs, not gamers :)
 
Generally speaking, but not always the timings aren't really what people buy a specific stick for, a 7,7,7,24 stick isn't necessarily better at 1333Mhz than 9,9,9,30+, but you might realise that the IC's on the lower latency chip scale better with more voltage and hit 2000Mhz more easily, though the reverse can be true, old school Bh-5 sticks just didn't like doing high latency so had a top limit while "worse" memory could go a lot further but be ultimately slower.

Its like anything else though, back when we were stuck on one core and software was made for it, Ghz was all important, once we got up to quads and software slower evolved not to need quads, but to spread the load, we basically got a massive level of spare power going on in most situations. Dual channel was actually a pretty major leap, many moons ago now, but with improving speeds the whole time and added, more impressive cache levels and efficiency improving pre-fetching massively well, a lot of the extra bandwidth is rather pointless at this point. Bring octo cores onto a dual channel setup with similar mem to what we have now and memory might start to come back into it again.

Its swings and roundabouts, theres always a bottleneck, removing a single bottleneck doesn't matter if theres another one. The amount of data memory can pass into the cpu is quite staggering anyway you can see that triple channel i7's aren't really any faster than their dual channel variants, so they clearly weren't bottlenecked by memory bandwidth/speed in the vast majority of situations.

Remember latency has also reduced drastically, because clocks are literally shorter the more you have, ddr with cl of 2, is equivilent in miliseconds to a CL of 4 at twice the speed. cas latency at 7 on 1600mhz memory compared to a CL of 2 at 250Mhz is far far lower latency.

the memory latency settings are also only one link in the "latency chain", which is maybe 1/3 of what it used to be.

Look at it this way, if CL of 2 at 200Mhz, is the same as CL of 8 at 800Mhz , then cL of 3 at 200Mhz would be the same as CL of 12 at 800Mhz. The range of CL is actually massively lower in comparison than it used to be due to the massive clock increases. To see the same difference in performance as the "old days" you'd need to be comparing CL 8 and 12.

In terms of DDR3 prices, I went for 1600Mhz stuff to give you a bit more overhead for finding a nice setup with overclocking. £90-100 gets you 4GB of memory from a quality maker who will give basically a life time warranty on it, I spent £100 the other day on mine because I've used G-skill before, have RMA'd with them before and I could get it asap.
 
Thanks for the input drunkenmaster. So if you had to choose between the two, which would you go for? (Assuming you won't OC past 1600MHz)

Corsair XMS3 6GB (3x2GB) DDR3 PC3-12800C7 (1600MHz) Tri-Channel (TR3X6G1600C7) - £199.99
Patriot Viper 6GB (3x2GB) DDR3 PC3-12800C8 (1600MHz) Low Latency Tri-Channel (PVT36G1600LLK) - £129.98

Or is this almost bordering on a stupid question?
 
gurusan said:
Get the Vipers for sure. 200 quid on ram is just silly
Click to expand...

+1. Only point in going high end is if you ram is actually holding you back. Spending £70 on a small upgrade could be put towards say an SSD which would give you a noticable difference.
 
gurusan said:
Get the Vipers for sure. 200 quid on ram is just silly
Click to expand...

beh* said:
+1. Only point in going high end is if you ram is actually holding you back.
Click to expand...

:D

ramk.png


:p:p:p:p:p (Sorry, I couldnt resist).

This stuff does 1600 Mhz @ 7-7-7-20.
 
Last edited:
drunkenmaster said:
Remember latency has also reduced drastically, because clocks are literally shorter the more you have, ddr with cl of 2, is equivilent in miliseconds to a CL of 4 at twice the speed. cas latency at 7 on 1600mhz memory compared to a CL of 2 at 250Mhz is far far lower latency.
Click to expand...

Very interesting, never knew you had to think about it like that! :O
Good post! :cool:
 
drunkenmaster said:
Generally speaking, but not always the timings aren't really what people buy a specific stick for, a 7,7,7,24 stick isn't necessarily better at 1333Mhz than 9,9,9,30+, but you might realise that the IC's on the lower latency chip scale better with more voltage and hit 2000Mhz more easily, though the reverse can be true, old school Bh-5 sticks just didn't like doing high latency so had a top limit while "worse" memory could go a lot further but be ultimately slower.

Its like anything else though, back when we were stuck on one core and software was made for it, Ghz was all important, once we got up to quads and software slower evolved not to need quads, but to spread the load, we basically got a massive level of spare power going on in most situations. Dual channel was actually a pretty major leap, many moons ago now, but with improving speeds the whole time and added, more impressive cache levels and efficiency improving pre-fetching massively well, a lot of the extra bandwidth is rather pointless at this point. Bring octo cores onto a dual channel setup with similar mem to what we have now and memory might start to come back into it again.

Its swings and roundabouts, theres always a bottleneck, removing a single bottleneck doesn't matter if theres another one. The amount of data memory can pass into the cpu is quite staggering anyway you can see that triple channel i7's aren't really any faster than their dual channel variants, so they clearly weren't bottlenecked by memory bandwidth/speed in the vast majority of situations.

Remember latency has also reduced drastically, because clocks are literally shorter the more you have, ddr with cl of 2, is equivilent in miliseconds to a CL of 4 at twice the speed. cas latency at 7 on 1600mhz memory compared to a CL of 2 at 250Mhz is far far lower latency.

the memory latency settings are also only one link in the "latency chain", which is maybe 1/3 of what it used to be.

Look at it this way, if CL of 2 at 200Mhz, is the same as CL of 8 at 800Mhz , then cL of 3 at 200Mhz would be the same as CL of 12 at 800Mhz. The range of CL is actually massively lower in comparison than it used to be due to the massive clock increases. To see the same difference in performance as the "old days" you'd need to be comparing CL 8 and 12.

In terms of DDR3 prices, I went for 1600Mhz stuff to give you a bit more overhead for finding a nice setup with overclocking. £90-100 gets you 4GB of memory from a quality maker who will give basically a life time warranty on it, I spent £100 the other day on mine because I've used G-skill before, have RMA'd with them before and I could get it asap.
Click to expand...

very interesting :) thanks for the info, never knew it was like that
 
i got the 2133MHz geil stuff too, crazy how much prices have gone up. Only recently got my RAM running beyond 1600MHz tho. it just wouldn't play!
 
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