Tref values

[qui]

take the value higher than what you calculate as almost none are accurate. my oc didnt prove to be stable after all however it was more stable than before when i was using the "favourite" 3072 value for my redlines.

[burningrave101]

no

lookup your HTT/Mem speed in the table. (or take a value close)

I looked it up in the table and came up with the same TREF value i got calculating my refresh rate times HTT speed.

I'm running 280Mhz with OCZ PC3200 Platinum Rev2 and the refresh rate in Everest is 7.8 us so 7.8 x 280 = 2184 and the next highest TREF value from that is 2336.

I'll try it out later and see if it helps stability any. Right now i'm not stable running 1:1 at 280Mhz 1T with this stupid Venice core. My Venice will overclock to 2.8Ghz+ but its memory controller seems crappy.

[mad mikee]

Bloody heck this formula has made all the difference, before i was only able to goto 250htt using 3072 without instant BSOD as soon as i began to stress test it, or over 2k errors on 1st pass of 5th test memtest, however switching to 2048 i am now at 260htt (priming), insidently 2048 gives exactly 7.8us. However I do find it odd how 3072 was not as stable considering it was a far more relaxed tRef??

So if you make the time between refreshes too far apart, you risk degradation / loss of data. OTOH if 2 close together, may interfere w/ timing. Then there is teh JUST RIGHT Tref.

I am adding another thread about 'wouldn't it be nice to allow us to enter our OWN tref value based on FSB?

[Jomiy]

Well I tested my OCZ Plat Rev 2 at Tref=2336 since 305*7.8 = 2379. Seemed a tiny bit less stable than 3072. Tested at 2560 and got past 5 passes Memtest #5.

Then again my RAM seems to be clocking better since 2 days ago it needed 2.93V to do 5 passes at 300 and yesterday it only needed 2.8V...

This morning I swapped in BH-5, Everest refresh said 7.8us, set Tref= 2048 for 250Mhz (7.8*250=1950) and comp wouldn't POST!

Had to clear CMOS and take battery out

[Cornelious0_0]

Well I tested my OCZ Plat Rev 2 at Tref=2336 since 305*7.8 = 2379. Seemed a tiny bit less stable than 3072. Tested at 2560 and got past 5 passes Memtest #5.

Then again my RAM seems to be clocking better since 2 days ago it needed 2.93V to do 5 passes at 300 and yesterday it only needed 2.8V...

This morning I swapped in BH-5, Everest refresh said 7.8us, set Tref= 2048 for 250Mhz (7.8*250=1950) and comp wouldn't POST!

Had to clear CMOS and take battery out

Weird....I like the fact that (for now) there seems to be an actual way to figure out what Tref value you "should" be using....but there's still too many people having issues with it for me to have full confidence.

[burningrave101]

Well I tested my OCZ Plat Rev 2 at Tref=2336 since 305*7.8 = 2379. Seemed a tiny bit less stable than 3072. Tested at 2560 and got past 5 passes Memtest #5.

Then again my RAM seems to be clocking better since 2 days ago it needed 2.93V to do 5 passes at 300 and yesterday it only needed 2.8V...

This morning I swapped in BH-5, Everest refresh said 7.8us, set Tref= 2048 for 250Mhz (7.8*250=1950) and comp wouldn't POST!

Had to clear CMOS and take battery out

I think your suppost to choose the next HIGHEST tREF value after you calculate instead of just the closest one which is lower then the number you calculated. Trying lowering your HTT/RAM speed to 280Mhz or so and try the 2336 tREF again or try the next higher tREF value.

[blackjok3r]

I did it!

This program will calculate the ideal tref values for 256mb and 512mb sticks. And then find the clostest value above the ideal one for you.

Download TrefCalc

[jcniest5]

I did it!

This program will calculate the ideal tref values for 256mb and 512mb sticks. And then find the clostest value above the ideal one for you.

Download TrefCalc

Does it help after you try the value this program calcalates for your setting?

[blackjok3r]

no you enter, the speed you want to run your stick at and choose the stick size. Then it will calculate the ideal tref and pick out the closet value above the ideal value.

[jcniest5]

no you enter, the speed you want to run your stick at and choose the stick size. Then it will calculate the ideal tref and pick out the closet value above the ideal value.

I know, but don't you have to enter that value in the TREF field in the BIOS?

[blackjok3r]

yes of course you do... whats the point of calculating it if you dont use it??

[zioxin]

Just wondering, what speed do you write in the field? 200 or 400?

[Jimbo Mahoney]

I did it!

This program will calculate the ideal tref values for 256mb and 512mb sticks. And then find the clostest value above the ideal one for you.

Download TrefCalc

Nice.

I think you really need to add an extra option of memory refresh if you know it.

Almost all memory seems to be 7.8us. 256MB normal memory is 15.6us, but our stuff (ie faster clocking etc) tends to be the same as 512MB, ie 7.8us.

HTH

[jiff]

nice work

[Agent-JCDenton]

Sup ya'll

Here's the test i ran to check for new ideal tref values:

All components as shown in my sig.

I know 260Mhz 2-2-2-5 is stable at 3.45v, but in memtest i always find its much easier to work with errors than a clear screen when searching for what settings are more stable than others...this will explain that:

vDimm: 3.38v (to cause a few errors, hopefully between 5-20 per pass in test 5)
FSB: 260
Timings: All tests ran using these

Using this excel sheet the ideal tref comes out to be 2031.25, which makes the following trefs candidates:
2064 (133Mhz - ?.?us) and 2048 (133Mhz - 3.9us).
To test for higher and lower ends of the scale i picked:
1552 (100Mhz - ?.?us) and 2560 (166Mhz - 3.9us).

I ran 5 passes of memtest test 5 for each tref:

Tref values | Average Errors Per Pass
----------------------------------------------------------
1552 (100Mhz - ?.?us) = 6-8
2048 (133Mhz - 3.9us) = 27-32
2064 (133Mhz - ?.?us) = 22-25
2560 (166Mhz - 3.9us) = 4-5

Increasing the vDimm back 3.45 and running 5 passes, 2560 was stable 1552 was ok (it gave me the odd 2 errors in pass 3). 2048 & 2064 were still giving me errors.

The trefs i use with my GH are 3684, 3120 & 2560 - 2560 seems to work with almost any memory on my setup.

[WeStSiDePLaYa]

OK READ THIS

if the refresh rate is TO SLOW data is corrupted correct? and if it is to fast then theoreitccly the sticks heat up more correct?

and if a lower value means it is refreshed more often, and a higher value means it is refreshed less often. then WHY do you want the next highest value? YOU DONT, that means there is more chance of data loss, you want the next LOWEST value would you not?

makes sense to me,

[amrgb]

There is one big assumption made here that must be questioned: the module's refresh time.

In the same way that, for instance, TCCD is rated with 2-2-2 timings @ 200, everyone knows that these timings won't work with say 280 fsb. The same thing may apply to the refresh rate.

Moreover, as previously stated, the optimal refresh rate may be affected in someway by the other timings.

Honestely, for me this is the theory that makes most sense when defining the Tref value. But I doubt that the optimal refresh period of a module running @ 280 will be the same when it was running at 200.

This leads us to the same starting point: try them all to find the optimum.

With my 2x512 TCCD @ 291 I've found that the best Tref is 780 or 908, far way from the value given by the formula (2270).

[magg]

What TCCD are you running? Because I've been reading through the various tREF threads this morning and have found from multiple places that the general theory sticks true to higher FSB's. As soon as I get off work, I was going to go home and try mine out [closest value came out to 2336, from 7.8 / (1/280) ].

What are the other timings / voltages you have as well?

BTW, this thread rocks, it's nice to actually see a thread that has uber-intelligence in it, instead of "is this rig any good?"....bleh

[amrgb]

You can see my timings here: http://www.xtremesystems.org/forums/...523#post905523

Its GSkill 4400 LE @ 2.8v (I haven't tried 2.7v yet)

[Agent-JCDenton]

OK READ THIS

if the refresh rate is TO SLOW data is corrupted correct? and if it is to fast then theoreitccly the sticks heat up more correct?

and if a lower value means it is refreshed more often, and a higher value means it is refreshed less often. then WHY do you want the next highest value? YOU DONT, that means there is more chance of data loss, you want the next LOWEST value would you not?

makes sense to me,

Have you ran any tests to confirm?

[flexy]

if you look at the table
++++++++++++++++++++++++++++++++++++
1552= 100mhz(?.?us)
2064= 133mhz(?.?us)
2592= 166mhz(?.?us)
3120= 200mhz(?.?us)(my sweat spot w/ Bh-6 at 250+mhz , your mileage may vary)
---------------------
3632= 100mhz(?.?us)
4128= 133mhz(?.?us)
4672= 166mhz(?.?us)
0064= 200mhz(?.?us)
---------------------
0776= 100mhz(?.?us)
1032= 133mhz(?.?us)
1296= 166mhz(?.?us)
1560= 200mhz(?.?us)
---------------------
1816= 100mhz(?.?us)
2064= 133mhz(?.?us)
2336= 166mhz(?.?us)
0032= 200mhz(?.?us)
---------------------
0388= 100mhz(15.6us)
0516= 133mhz(15.6us)
0648= 166mhz(15.6us)
0780= 200mhz(15.6us)
---------------------
0908= 100mhz(7.8us)
1032= 133mhz(7.8us)
1168= 166mhz(7.8us)
0016= 200mhz(7.8us)
---------------------
1536= 100mhz(3.9us)
2048= 133mhz(3.9us)
2560= 166mhz(3.9us)
3072= 200mhz(3.9us)
---------------------
3684= 100mhz(1.95us)
4196= 133mhz(1.95us)
4708= 166mhz(1.95us)
0128= 200mhz(1.95us)
++++++++++++++++++++++++++++++++++++


you see that the formula

uS x FSB does NOT always apply.

check the table for yourself.

3.9 x 100 = 390 - table says 1536

ALSO...the other BIG question.....yes indeed we dont even know if we NEED to change the TREF...if the TREF has to be increased if we go higher with the HTT/FSB

At this point i THINK all this theory here is pure speculation - the only definitive answer we could get from someone at Samsung or someone who really KNOWS what the values mean in the bios and what they're supposed to be.

Maybe even Oscar just follows specs without being able to tell what's the optimum for certain speeds etc.

THEN....of course the odd values (0016 etc.) which are totally non-logical..and AFAIK 0016 also does not work and you get freezes instantly. Wonder if those values are just plain wrong.

[Jimbo Mahoney]

I think the table is wrong.

It has just been formulated based on what a piece of software interprets the refresh rate to be.

[flexy]

With my 2x512 TCCD @ 291 I've found that the best Tref is 780 or 908, far way from the value given by the formula (2270).

How do you define "best" ?

Like in best performance eg. more bandwidth ?

Or more stability ?

I am sitting for months already on the problem to get my sticks to do 2.5 3 3 7 at 291 (best i can do is 2.5 4 3 7)...and "best" would be (for me) more stability.

Someone else maybe means "best" because he says 50MB bandwisth increase but even more instability ?

[Jimbo Mahoney]

OK READ THIS

if the refresh rate is TO SLOW data is corrupted correct? and if it is to fast then theoreitccly the sticks heat up more correct?

and if a lower value means it is refreshed more often, and a higher value means it is refreshed less often. then WHY do you want the next highest value? YOU DONT, that means there is more chance of data loss, you want the next LOWEST value would you not?

makes sense to me,

Well, you just have to try values either side of the ideal. There will almost always be one value which is closer to the ideal, so just use that one.

I would say too high and too low are both equally bad. They both cause errors.

[Jimbo Mahoney]

There is one big assumption made here that must be questioned: the module's refresh time.

In the same way that, for instance, TCCD is rated with 2-2-2 timings @ 200, everyone knows that these timings won't work with say 280 fsb. The same thing may apply to the refresh rate.

Moreover, as previously stated, the optimal refresh rate may be affected in someway by the other timings.

Honestely, for me this is the theory that makes most sense when defining the Tref value. But I doubt that the optimal refresh period of a module running @ 280 will be the same when it was running at 200.

This leads us to the same starting point: try them all to find the optimum.

With my 2x512 TCCD @ 291 I've found that the best Tref is 780 or 908, far way from the value given by the formula (2270).

Interesting point. I don't know enough about memory technology to state whether the ideal refresh period changes with speed.

Is there a chance you have 3.9us memory? That would mean the ideal Tref @ 291 is 1135, which is at least close to the 780 and 908 you use.

Also, as already mentioned, is that a stability or bandwidth 'best'?