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Alex-Ro
Level 10
please delete
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1 REPLY 1

Alex-Ro
Level 10
ISSUE #2

I am stuck at 55 41 78 or 3E POST CODE

Encountered this a lot,usually:
3E means too low Write Recovery / read to precharge time
78 means too tight TRCD/TRP
41 Means you went too tight on tertiary or you pushed too much voltage on Hynix MFR
55 well this means a lot,from not enough voltage for give settings,too tight TRFC ,improper tertiary.


ISSUE # 3


General behavior of various IC

Hynix MFR is the classic of X99 and actually the WORST performer on AIR . It has many problems on AIR,meaning hard to get high frequency and tight CAS . Worst voltage tolerant IC , creates many problems like you can pass DDR4-3200 12-15-15 at 1.58 V, 1.54V gives can?t train 55 and 1.62V gives you 41 because the voltage is too high . The best sticks to look for are the ones that support higher voltages at higher speeds , good sticks can bench DDR4-3200 12-15-15 under 1.6V and with good voltage tolerance they might get you to DDR4-3333 12 +


Hynix AFR is the improved die from Hynix . Fixes many of MFR flaws and it?s a huge improvement . Can tolerate high voltage at high speeds and run great on X99 and Z170 . They will be available very soon on Kingston HyperX memory and other vendors will implement too for sure.

Typical benching scenarios are
DDR4-3600 12-17-17 at 1.65
DDR4-3733 12-18-18 at 1.75
DDR4-3866 13-18-18 @1.85
DDR4-4000 13-19-19@1.94

Of course voltage might vary and be aware they are harder to clock compared to Samsung,my few sticks can?t manage over DDR4-3733 on any board but Impact ( 1 dimm per channel board)

Samsung D-Die K4A4G085WD


First die from Samsung has good voltage tolerance and can be found on a lots of modules from different vendors from Gskill 3000,3200 Ripjaws,early 3466 and 3600 Ripjaws-V and Trident-z to Corsair lineup and so on . Can go up to 2-2.1V on air and scaling is linear .
Typical benching scenarios are at DDR4-3733 15-19-19 for worser kits with 1.8-1.9V to better sticks doing even 13-18-18 .

Samsung E-DIE K4A4G085WE


Second revision from Samsung gained huge improvements . Voltage tolerance is great,taking up to 2.1V at 4200+ speeds ,trcd limits have gone lower and overall it looks like a very solid IC.
Typical benching scenarios are:
DDR4-3600 11-17-17 at 1.9V and under
DDR4-3866 11-19-19 at 2.05V and under
DDR4 -4000 12-20-20 at 2V and under

So far to be found on G.skill Trident-Z and Ripjaws-V kits on week 38 and higher , Teamgroup inferior bin of 3866 18-22-22 and newly Corsair 4000c19 .
The best modules to aim for are low TRCD ones, generally aim for DDR4-3600 TRCD/TRP 17 and DDR4-4000 TRCD/TRP 19 . They are the easiest to clock modules and also can go lower in tertiary/secondary ,TRFC of 280 at 4200 speed should not be a problem for good sticks.

ISSUE # 4


2 DIMM vs 4 DIMM

4 DIMM is ALWAYS faster than 2 DIMM at similar clocks/timings . Early results in XTU benchmark showed that , however this puts more stress on IMC and result in looser timings sometimes. The only timing to be adjusted is TWRWR_DD which has to be 8 otherwise platform will not start.
Keeping identical secondary/tert timings at same clock speed on 4 ghz 32M test this is about 1 second faster at DDR4-3466 C12 which is quite a difference in 32M world.




Please NOTE that AUTO RTL/IOL on 4 DIMM scanarios will give you very loose IOL,this is because Maximus boards will automatically set IOL_latency offset 15 instead of default 21 when 2 dimms are used. Easy way to fix this is to manually set 21 for better performance.


ISSUE # 5

BAD RTL Training

Sometimes the memory training is missed and you can see big difference in RTL/IO,for example instead of 50/51/7/6 you will have 58/51/14/6 and similar.This WILL hurt the performance a lot in 32M and XTU too,It is always best when finding proper RTL/IOL combo to manually lock them by overriding AUTO so you will have same values every time.

Example : Samsung D 3733 C14 normal RTL vs fail RTL :



ISSUE #6

The TWRWR_DR and TWRWR_DR timings .

Being advocated to go as low as it can this is actually a big lie as tested on all ic available I had found that going lower actually hurts and optimum value for high and medium speeds is actually 8 .
Tested on MFR,Samsung E-die and Kingston AFR,4 4 is worser than 8 8 period .
AFR DDR4-3866 13-18-18
TWRWR_DR TWRWR_DD 8 8

TWRWR_DR TWRWR DD 4 4

0.400 Sec Worse
E-DIE DDR4-4133 12-20-20 TWRWR_DR TWRWR_DD 8 8

TWRWR_DR TWRWR DD 4 4

0.300 Sec Worse
Hynix MFR DDR4-3200 12-15-15 TWRWR_DR TWRWR_DD 9 9 same as 8 8 result

TWRWR_DR TWRWR_DD 4 4


1 SECOND Difference at slower times !

ISSUE #7

TWRRD_DR and TWRRD_DD
Actually encountered this issue when I left this timing on AUTO and went from DDR4 3466 C12 to C11 and got a worser score !. After a few tries I found that AUTO gave me 6 6 and after lowering this to 5-5 performance gain was normal . It actually can go lower to 4 4 and 3 3 but performance was similar to 5-5 on Hynix AFR and worser on Samsung E-die and stability was a little bit worse so I would recommend 5-5 in all cases period.

Example:

Hynix AFR DDR4-3466 C12 Twrrd_dr , dd at 5 5 : 7 26 110

DDR4-3466 C11 TWRRD_dr dd at 6 6 7 26 281

DDR4-3466 C11 TWRRD_dr dd at 5 5 : 7 m 25 672

Samsung E-die 4133 12-20-20 TWRRD_dr dd 4 4 : 7.23.719

Samsung E-die 4133 12-20-20 TWRRD_dr dd 5 5 : 7.23.562


ISSUE #8

TWRRD_SG and TWRRD_DG

General rule is that they go tighter with CAS going lower and they are linked with Write to Read Delay L and S . Write to Read Delay L and S can go lower than 6 even to 1 but show no performance increase whatsoever,except when lowering them by TWRRD_SG and TWRRD_DG.



For example the settings pictured above resulted in showing 7 7 for write to read delay L and S although they were set at 6 in UEFI .



Lowering TWRRD_DG from 22 to 18 resulted in showing 7 and 3 :



The performance boost is little but might matter on

Since we are talking about Write to Read Delay(not L and S), this timing can go as low as 1 and see little performance boost

ISSUE #9

TRDRD_dr and TRDRD_dd

This is actually interesting because of conflicting results.While testing IC from Hynix and Samsung I noticed that Hynix prefers this two timings at 0 0 gaining almost half a second boost while Samsung prefers the other way around having the best results at 5 6 .Even complementary values like 4-5 5-5 6-7 gave worser results so my findings are that if you own a Samsung based memory this have to be set at 5-6 while Hynix likes them at 0-0.

Example :

Samsung D-Die 3733 14-19-19
TRDRD_dr + dd 0-0  7.26.172

TRDRD_dr+dd 4-5  7.26.000

TRDRD_dr+dd 5-6  7.25.844

Hynix AFR 3866 13-18-18
TRDRD_dr+ dd 5-6  7.24.172

TRDRD_dr+dd 0-0  7.23.969