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Memory OC - Advice needed.

8K views 41 replies 8 participants last post by  Iwamotto Tetsuz 
#1 ·
Hi,

I have a single Corsair Vengeance LP 8GB RAM stick installed (cml16gx3m2a1600c10) - http://www.corsair.com/en-gb/vengeance-low-profile-16gb-dual-channel-ddr3-memory-kit-cml16gx3m2a1600c10

The default (X.M.P) settings for the RAM stick were
1600MHz with Timings: 10,10,10,27 with CR - 2

I was reading around on OC'ing my RAM and read how CR 1 is better than CR 2 then saw few other posts saying how it doesn't matter much etc but went ahead and changed it to CR 1. So far it was good.

Then I went ahead and tried to OC my memory.
I went from

1.5V - 1600MHz - 10,10,10,27,CR-1

To

1.65V - 1866MHz - 10,11,11,31,CR-1

I did a few benchmark tests in AIDA64 and the read,write and latency improved slightly.

Default settings 1600MHz - 10,10,10,27,CR-1 @ 1.5v
Read: 12560mb/s
Write: 12489
Latency 57.3ns

New settings - 1866 - 10-11-11-31-CR1 @ 1.65v
Read: 14571
Write: 14527
Latency: 52ns

I suppose this is a small change, but I was hoping If I could get some advice on whether this small OC was worth it. I do not go for benchmark scores or anything, i mainly use my computer for gaming, and currently trying to squeeze whatever performance I can out of my old rig.

Specs:
i5 3570k @ 4.3GHz 1.2v
8GB RAM^
MSI GTX 970 (OC'd)
PSU: Corsair TX650

Was this OC worth it for possibly a small performance boost? Adding the extra voltage and messing with the frequency and timings, or should I just go back to stock, 1600MHz 10,10,10,27,CR1.

Thanks for your time.
 
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#2 ·
Of course overclock your memory!

Why only one stick from the kit?

SuperPi is a nice quick and dirty memory benchmark program. Just run the 1M setting with each different overclock and average out three runs for each.
Then take the two or three best overclocks and bench them with FutureMard, Cinebench or FurMark. (or all three!)

Be aware that different games benefit differently from memory overclocking. Some almost not at all.
 
#3 ·
Thanks I'll check that out.

Sadly I got this PC quite a while back and my knowledge in computers was quite bad. (Got it custom built) and the specification was 8GB but they decided to put a single 1 stick in. Not sure if dual 4gb sticks would of been better or not.

Should I expect a good gain in game performance in general by OC'ing my memory? or will it be minimal.

Apart from SuperPi, is there any other memory test I should use? Such as HCIDesign MemTest?

Also if you could give me a rough idea of what a good RAM OC would be that would be great. Like frequency's and Timings that I should stay around - Because I know we're just meant to change the main 4 frequencies but I am not sure which out of them all I should be changing first, which I should aim to keep the lowest etc. If you could like me a good guide or explain this to me if you have that, that would be really awesome.

Thanks again
smile.gif
 
#4 ·
1600 to 1866 is a 16% overclock and memory is about 3% of performance for modern CPUs.
So 3% of 16% is only about 0.5% performance gain.

Run the memory at 1600 with defaults set for all the timings.and write down what they default to.
Manually set all the timings to those and then start slowly raising the memory speed until it won't boot.
Then try raising the other three timings and see if you can get it to boot.

A little tome I wrote about memory timings:

Memory latency, or timings, like the number 10 in CL 10, are the length of time it takes the memory to complete a step in what it has to do. That "time" is measured in "clock ticks", ie CL 10 takes 10 clock ticks to complete before the memory can move on to it's next operation. The length of one clock tick is the speed at which the memory is running. 1800 MHz memory has a clock tick length of one 1,800,000,000th of a second (1,800,000,000 clock ticks per second), so the CL step takes 10 x 1/1,800,000,000 seconds.

A stick of memory always takes the same amount of time to complete it's CL step (or any other step) no matter what speed it is running. If you run the above memory stick faster, say 2400 MHz, it still takes 10 x 1/1,800,000,000 seconds to complete the CL step, but each clock tick is now 1/2,400,000,000 of a second, so it now would take more clock ticks to complete the CL step. Namely, 24/18 times 10 (for CL step) or 13.3 clock ticks (10 times 24/18 clock ticks). But, alas, that has to be rounded to to CL 14 as memory can't use partial clock ticks.
 
#5 ·
I was playing GTAv for hours with no problems. But went into Mafia 3 and blue screened within minutes. I will reset and OC my memory using your method. Is it okay for me to start off at 1.65v and find a good stable OC then try lower the voltage once stable?

I know I cant boost when going over 1600MHz at default timings despite using 1.65v. but what I am unsure about is which one of the 4 timings should I increase first. Or does it not matter.

Also you said to adjust the other 3 timings. But am I not also increasing the 4th timing? E.g. 10-10-10-27 (would I not increase the 27 slowly too? To help with the OC.

As I am new to OCing ram I struggled a bit to understand the 2nd paragraph of your explanation.

I'll do more research into RAM OCing and check out some videos too tomorrow.

I appreciate all the help you're giving me!

EDIT: Since I can't increase the frequency without increasing the timings. I may try keep the frequency the same and lower the timings. I guess that may provide better results for me? Will increasing the voltage help in this sktuation? (Starting at 1.65v and lowering if stable).
Also should I keep my Command Rate at default 2N or is it better to use 1N if stable for performance?
 
#6 ·
Of all the timings CAS will have the most effect on performance.
1.65 volts is kind of hard on memory. maybe OK for a temporary overclock for benchmarking. I'd stick to 1.6 volts for an "everyday" overclock.

Leave the command rate at 2T
When the MC (Memory Controller) first tries to access memory, it has to latch onto a memory bank, known as CS (Chip Select). Then it proceeds to find the column (CAS), the Row (RAS), and then return the data to the CPU. Now, 1T means it takes 1 clock cycle to "find" a memory bank, vs. 2T where it takes 2 clock cycles to "find" the memory bank. But there's a sorta quirk, this only happens the first time data is attempted to be fetched from memory, and all subsequent accesses to that chip are done w/o delay, making the command rate null after the initial chip fetch.


 
#7 ·
http://www.overclock.net/t/1536669/perfect-ram-timing-rule-posting-resuts-of-using-the-rule-is-appreciated
have a look through my ram timing rule.
If you don't understand how it works take a screen shot of your bios ram timings and I'll give you a few sets of timings to try out

Guys may dissagree
But I think that 1.8Volts is alrright for daily usage even on air.
I reckon that you should use mem test to occupy your ram and run it for an hour and touch your ram to see how hot it is. If it dosen't burn your hand then its good.
I had ran ram at real high voltages like 1.96Volts on air cooling. And I still have those rams today in working condition and seen zero degration.
 
#8 ·
#9 ·
Quote:
Originally Posted by billbartuska View Post

Of all the timings CAS will have the most effect on performance.
1.65 volts is kind of hard on memory. maybe OK for a temporary overclock for benchmarking. I'd stick to 1.6 volts for an "everyday" overclock.

Leave the command rate at 2T
When the MC (Memory Controller) first tries to access memory, it has to latch onto a memory bank, known as CS (Chip Select). Then it proceeds to find the column (CAS), the Row (RAS), and then return the data to the CPU. Now, 1T means it takes 1 clock cycle to "find" a memory bank, vs. 2T where it takes 2 clock cycles to "find" the memory bank. But there's a sorta quirk, this only happens the first time data is attempted to be fetched from memory, and all subsequent accesses to that chip are done w/o delay, making the command rate null after the initial chip fetch.


picsnip
Understood, I'll stick to a lower voltage to start with, 1.55 then move to 1.60 and possibly 1.65 if I am getting nowhere. Also I'll swap the MC back to 2T for better stability
smile.gif
.
Thanks for that picture that helps a lot to make sense of what affects what.

Quote:
Originally Posted by Iwamotto Tetsuz View Post

http://www.overclock.net/t/1536669/perfect-ram-timing-rule-posting-resuts-of-using-the-rule-is-appreciated
have a look through my ram timing rule.
If you don't understand how it works take a screen shot of your bios ram timings and I'll give you a few sets of timings to try out

Guys may dissagree
But I think that 1.8Volts is alrright for daily usage even on air.
I reckon that you should use mem test to occupy your ram and run it for an hour and touch your ram to see how hot it is. If it dosen't burn your hand then its good.
I had ran ram at real high voltages like 1.96Volts on air cooling. And I still have those rams today in working condition and seen zero degration.
Thanks I'll definitely check your post out looks useful!

Also here is a screenshot of my BIOS timings, I'm interested to see what you recommended. So I can get an idea of what to work with also.
https://dl2.pushbulletusercontent.com/ix5LvNTYaS0biRrYMNZwUt7CqfINoHKs/20161011_130803.jpg
 
#10 ·
Since you're interested in what does what, here's more info than you probably want:

Refresh Rate (tRFC)

Memory stores ones and zeros as charged and uncharged capacitors,
Billions of them! - a 4 Gig stick has 4.000,000,000 capacitors - arranged in rows and ranks.

A charges capacitor represents a one and an uncharged capacitor equals a zero.
The problem with capacitors is that they slowly loose their charge.
So, periodically memory has to stop whatever it's doing and refresh all the ones and zeros. That takes time.
If it doesn't happen often enough and capacitors loose their charge whatever is stored in memory gets corrupted. (Note, not lost, but corrupted - see below.)
If it happens to often then the memory is wasting time refreshing data when it isn't yet necessary to do so.

When you increase memory voltage you're putting more charge into the charged capacitors, and it takes longer for then to leak down.
To much voltage for to long destroys capacitors.
Refreshing the capacitors more often can be equivalent to increasing voltage. You can run lower voltages at higher speeds with higher refresh rates.

So adjusting tREF can make memory stable and/or increase performance.
But it has to be adjusted just right between to much and not enough time to work the best.

Corruption:
When CAS or many other timings are set to low the memory just stops working, and, usually, the computer just freezes.
So you just reboot, enter the BIOS and change the offending setting.

But, with tREF the memory keeps working, but any data the memory handles gets corrupted.
That most often results in a corrupted OS. The computer becomes a boat anchor until you reinstall - everything.

One easy way to avoid this is to install a second copy of your OS. Your current key will work and you don't need any Windows updates. just a few drivers.
If you use that install to do all your memory tweaking it makes life a lot easier. Once you figure out what you want to do you can set up your memory overclock on your main OS.

Maximum Asynchronous Latency also has a great effect on stability.
 
#11 ·
Quote:
Originally Posted by billbartuska View Post

Since you're interested in what does what, here's more info than you probably want:

Refresh Rate (tRFC)

Memory stores ones and zeros as charged and uncharged capacitors,
Billions of them! - a 4 Gig stick has 4.000,000,000 capacitors - arranged in rows and ranks.

A charges capacitor represents a one and an uncharged capacitor equals a zero.
The problem with capacitors is that they slowly loose their charge.
So, periodically memory has to stop whatever it's doing and refresh all the ones and zeros. That takes time.
If it doesn't happen often enough and capacitors loose their charge whatever is stored in memory gets corrupted. (Note, not lost, but corrupted - see below.)
If it happens to often then the memory is wasting time refreshing data when it isn't yet necessary to do so.

When you increase memory voltage you're putting more charge into the charged capacitors, and it takes longer for then to leak down.
To much voltage for to long destroys capacitors.
Refreshing the capacitors more often can be equivalent to increasing voltage. You can run lower voltages at higher speeds with higher refresh rates.

So adjusting tREF can make memory stable and/or increase performance.
But it has to be adjusted just right between to much and not enough time to work the best.

Corruption:
When CAS or many other timings are set to low the memory just stops working, and, usually, the computer just freezes.
So you just reboot, enter the BIOS and change the offending setting.

But, with tREF the memory keeps working, but any data the memory handles gets corrupted.
That most often results in a corrupted OS. The computer becomes a boat anchor until you reinstall - everything.

One easy way to avoid this is to install a second copy of your OS. Your current key will work and you don't need any Windows updates. just a few drivers.
If you use that install to do all your memory tweaking it makes life a lot easier. Once you figure out what you want to do you can set up your memory overclock on your main OS.

Maximum Asynchronous Latency also has a great effect on stability.
That was actually a really good read, thank you for that.
 
#12 ·
It looks like I am able to keep default voltage and set the frequency and timing to, 1600MHz 9-10-10-27 [CR 1]

I'm assuming this is better than my default 1600MHZ 10-10-10-27 but by a very small factor? Would it be this be okay for now, or would my RAM work better/efficient/stable if I was able to get it stable at something like 9-9-9-27 or 9-9-9-24.

The question I am trying to ask is, is it fine for the timings not to match like 9-9-9, and lower any timing that I can as long as my RAM is stable, or is it better to match them. (I'm asking this as I see a lot of 1600MHz and 1333MHz with 9-9-9-(24) timings.

Thanks again
biggrin.gif
 
#13 ·
you can try 2133 with 11-12-12-33-2T-9-45-AUTO-14-5-23-10-auto
11-13-13-34-2T-9-47-AUTO-14-5-23-10-auto
10-12-12-30-2T-8-42-AUTO-14-4-22-9-auto
10-11-11-29-2T-8-40-AUTO-14-5-23-9-auto
11-11-11-32-2T-9-43-AUTO-14-5-23-10-auto

you can try 1866 with
10-11-11-29-1T-8-40-AUTO-14-5-23-9-auto
9-11-11-27-1T-7-38-AUTO-12-5-23-8-auto
10-10-10-28-1T-8-38-AUTO-14-5-23-9-auto
9-10-10-26-1T-7-36-AUTO-12-5-23-8-auto

you can then drop back to 1T if your system boots and runs mem test stable
http://hcidesign.com/memtest/download.html
download the free ver and open a few coppies of mem test set each to run 2GB and monitor to occupy all ram,but leave 1GB of ram unsed.
Each coppy of mem test occupies a core so you'll also be stressing the cpu

if you got 2133 working properly I'll give you a set of 2400 and 2600 timings to try out

9/1600=0.005625
10/1600=0.00625
0.00625/0.005625 = 11.11111%Faster running Cl9 at 1600mhz
 
#38 ·
you can try 2133 with 11-12-12-33-2T-9-45-AUTO-14-5-23-10-auto
11-13-13-34-2T-9-47-AUTO-14-5-23-10-auto
10-12-12-30-2T-8-42-AUTO-14-4-22-9-auto
10-11-11-29-2T-8-40-AUTO-14-5-23-9-auto
11-11-11-32-2T-9-43-AUTO-14-5-23-10-auto


you can try 1866 with
10-11-11-29-1T-8-40-AUTO-14-5-23-9-auto
9-11-11-27-1T-7-38-AUTO-12-5-23-8-auto
10-10-10-28-1T-8-38-AUTO-14-5-23-9-auto
9-10-10-26-1T-7-36-AUTO-12-5-23-8-auto

you can then drop back to 1T if your system boots and runs mem test stable
http://hcidesign.com/memtest/download.html
download the free ver and open a few coppies of mem test set each to run 2GB and monitor to occupy all ram,but leave 1GB of ram unsed.
Each coppy of mem test occupies a core so you'll also be stressing the cpu

if you got 2133 working properly I'll give you a set of 2400 and 2600 timings to try out

9/1600=0.005625
10/1600=0.00625
0.00625/0.005625 = 11.11111%Faster running Cl9 at 1600mhz
Hello I'm happy I have found this thread as before posting it has already helped me,

First of all I am sorry to bump such an old thread but hey you get it where you can :)
I have the exact same rig as the OP but I followed through the guide and managed to bump my timings to the one above mentioned on 2133 10-11-11-29-2T-8-40-AUTO-14-5-23-9-auto but on 1.65v
and so far so good been stressing the mem and cpu for an entire hour all is running smooth even benchmarks are much faster i am still at a loss about ram timings and i dunno if the number goes higher or lower is it better or not? I tried the other timings you provided but this one on benchmarks seems to look the fastest. do you have any tighter timings I can try? And also as OP I left REF on auto as it would not post if I change it to ANY value except what it is on I think 307.

Much appreciated mate in advance thank you
 
#14 ·
Thank you, I'll work my way up to these timings.

Is it necessary to to change the other timings after the standard X-X-X-X-CR. As I don't feel comfortable changing these (don't want to accidentally damage my RAM/OS etc).
Could I leave these as AUTO and still hope to get a good OC/Stable or would changing these additional values help a lot towards the OC.
 
#16 ·
So I tried the timings, only adjusting X-X-X-X-CR and had no luck with 2133MHz but was get past POST and into windows on 1866MHz 10-11-11-29-1T, however, I ran MemTest (HCI) and it looked fine and it was showing no errors, but then it would randomly blue screen with different error codes each time. I also changed the CR to 2 but no luck and loosened the timings to 12-13-13-31 but still no luck unfortunately.

Currently I've set it back to what seemed to work for me without any visible issues at 9-10-10-27-1T @1600MHz.

Also whilst in this process of OCing my ram I've encountered a lot of BSOD's and crashes and it seems like it's affected my OS.
I will see the ASUS splash screen at the start for 15 seconds before it responds to me pressing DEL or bios or moving on to boot up windows, and when I get to the Windows boot up I will see the windows logo (with a spinning loading icon) for another 10-15 seconds. But once I am in my OS everything seems fine and speedy. I made sure that the ASUS splash screen time hasn't change (I left it at 2 seconds originally by changing it in the BIOS). - Could I have damaged something? I ran sfc /scannow but that didn't solve any issue on my windows loading and I've also got only my SSD as my boot option and disabled my 2nd SSD and 3 HDDs from being checked at boot.

Quote:
Originally Posted by Eterz View Post

I'd say keep the xmp settings and adjust frequency and voltage, it will provide the most stable results as far as I know. Also don't forget to adjust VCCIO and VCCSA if those aren't adjusting automatically
I may consider increasing this voltage after I research into it a bit more, would this affect CPU temperature? As I already hit quite high temps (72-77) under heavy load while gaming.

_________

Thanks for all the info people!
 
#17 ·
Quote:
Originally Posted by bhstr99 View Post

Thank you, I'll work my way up to these timings.

Is it necessary to to change the other timings after the standard X-X-X-X-CR. As I don't feel comfortable changing these (don't want to accidentally damage my RAM/OS etc).
Could I leave these as AUTO and still hope to get a good OC/Stable or would changing these additional values help a lot towards the OC.
Whenever you overclock ram, you have to change all timings, otherwise it will not work.
The bios is dumb and dosen't know how to set proper timings, you'll get the wrong timings in the wrong place if you leave it on auto.

You can't damage ram by changing timings, you'll only damage it by chaging the voltages

are you loading all of your ram? using mem test? a signle coppy 2gb running is not enough stress.

Try fully setting your timings and try again, I think you'll be able to run at least 1866 stable
 
#18 ·
Quote:
Originally Posted by Iwamotto Tetsuz View Post

Whenever you overclock ram, you have to change all timings, otherwise it will not work.
The bios is dumb and dosen't know how to set proper timings, you'll get the wrong timings in the wrong place if you leave it on auto.
Uh, that's what the SPD tables are for.
When you change memory speed the BIOS uses the correct timings for that speed.
If it didn't work that way any motherboard ever sold would only boot at one memory speed by default - The nOObs would go ballistic!

XMP - that's a different story. I stay as far away from XMP as I can get!
 
#19 ·
From my exprience,
The bios always sets you wrong timings, if you have 1866 ram. and you leave stuff on auto. everything gets set to 1866 ram timings, otherwise it will be unbuffered ddr3 ram timings which will never match up with other timings, and you want to go 2133 MHZ then you'll fail

When I had 1600 ram and topped out at 2008MHZ max oc, 1600-2000mhz oc is pretty much maximum a average guy can do if they do not set perfect timings
but then perfecting the timings manually gave me a maximum oc of 2240mhz no voltage increace same cooling used
 
#20 ·
Quote:
Originally Posted by Iwamotto Tetsuz View Post

are you loading all of your ram? using mem test? a signle coppy 2gb running is not enough stress.

Try fully setting your timings and try again, I think you'll be able to run at least 1866 stable
Hi, yes I was running 4 copies of MemTest, two 2gb and the other two were something around 1gb and 600mb to make sure I had around 800mb-1gb free RAM.
I never saw any errors but I would just get a bluescreen and crash.

Just to confirm for example the first set of timings you gave me (11-12-12-33-2T-9-45-AUTO-14-5-23-10-AUTO) , is this correct? I just want to make sure because it looks like a big jump from a high value to lower value on some of the timings.

https://i.gyazo.com/1b62cbd8c1676d109750f9cfd2510862.jpg
 
#21 ·
Small is better than nothing. I state I cannot experience your situation but for mine, that small bump I do notice a significant performance increase.

Here is my settings on totally different setup. My system is fast! Being so old and all but still it packs a punch with these settings @ stable i might add.

My system was not stable after 4.5ghz, so I supplemented little ram speed to supplement the rest of the overclock of my pc. WAS NOT EASY.

And my timings are tight as hell.

 
#22 ·
For the REF cycle Time you may want to leave it on default 208, and if it boots then try 45
Otherwise all you do is input the numbers from top to bottom in the order I gave it to you
 
#23 ·
Quote:
Originally Posted by HITTI View Post

Small is better than nothing. I state I cannot experience your situation but for mine, that small bump I do notice a significant performance increase.

Here is my settings on totally different setup. My system is fast! Being so old and all but still it packs a punch with these settings @ stable i might add.

My system was not stable after 4.5ghz, so I supplemented little ram speed to supplement the rest of the overclock of my pc. WAS NOT EASY.

And my timings are tight as hell.

-snip-]
Wow that's really nice.

____________________________________________
Quote:
Originally Posted by Iwamotto Tetsuz View Post

For the REF cycle Time you may want to leave it on default 208, and if it boots then try 45
Otherwise all you do is input the numbers from top to bottom in the order I gave it to you
Hi, I tried the timings you gave me, I had no luck with 2133MHz.

Similarly with 1866MHz, none of them would POST apart from the first one (10-11-11-29-1T-8-40-AUTO-14-5-23-9-auto) but then that would crash before it loaded windows properly.

Also every time I go through a few failed attempts, when I do manage to get into windows it takes me to "Preparing automatic repair" then a bunch of options come up so I select Continue to Windows which will then load up windows.

So for the 10-11-11-29-1T-8-40-AUTO-14-5-23-9-auto attempt, this is what I saw in order.





So I didn't even get to continue into windows before it BSOD'd

I restarted and another BSOD with same timings.



So for now I've went back to 1600MHZ - 9-10-10-27-1 -> rest Auto. and is stable at this.

__
Does anybody know why my boot splash screen (screen where you have to option to load into BIOS) is up for way over 10seconds just sitting there before it reacts to any of my keyboard input or moves on to load windows? Also windows is just sitting there spinning and loading for another 10 secs before seeing the desktop. Using SSD. Samsung 850 EVO.
 
#26 ·
Whats your ram voltage for 1866? You need to give it at least 1.65Volts

10-11-11-29-1T-8-80-AUTO-14-5-23-9
Try this change the timing from 40 to 80

for other timings cause they are tighter you need more voltage to boot, cause they operate faster.
Theres no such thing as free lucnch you have to earn it in same way, same with ram overclocking you have to give it more voltage or more cooling/ subzero

You could easliy run 1600 with decreaced CL going from cl9 to cl8 with increaced ram voltage saves the hassle with all the timings

9/1600=0.005625
10/1866=0.005359

0.005625/0.005359=1.05= 5% faster than 1600 MHZ which means you need a higher volatge to sustain the faster clocks

10-12-12-30-1T-8-42-AUTO-14-5-23-9

11-12-12-31-1T-8-43-AUTO-14-5-23-9 (This timing should be slightly slower than 1600 at CL9 you should be able to run this at stock voltage if not then the secondary timings I gave you are too tight)

for the 42,43 timing part could leave it at auto, stress for stabiliblty then go try 42 or 43
you can also try this as the timings could have been too tight
 
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