Soldato
- Joined
- 18 Oct 2002
- Posts
- 6,669
Been playing around with tREF on my system in sig.
With the memory @ 250 Mhz @ 2-2-2, 1T, 200 divider, I got the following graph:
EDIT - Yellow line shows 2GB OCZ @ 213 Mhz.
As you can see, a clear relationship between tREF and errors, and a slight reduction in bandwidth @ low tREFs.
My questions are:
Is the ideal tREF specific to the RAM?
Is it specific to the memclock?
Is it specific to the divider?
From previous discussions, I'm quite a fan of the following:
ideal tREF = refresh rate / (1/clockspeed)
The problem is that there is so much mis-information about tREF about, and that table showing tREFs grouped into refresh rates (3.9, 7.8, 15.6 us) and clockspeeds (100 - 200 Mhz) only confuses things. Don't even get me started on Dracula's tREF tables .
Does anyone have any simple theory on tREF?
At least Dracula's four best and four worst tREFs bear some resemblance to my findings:
Four best =
* 1560
* 3072
* 3120
* 4708
Four worst =
* 0016
* 0032
* 0064
* 0128
My four best (1GB BH5) =
* 3684
* 3072
* 4708
* 4196
EDIT - My four best (2GB OCZ) =
* 2336
* 2048
* 2560
* 1536
I can only assume higher tREF = better, but knowing that the memory must be refreshed to keep the data 'alive', a higher tREF could also result in data loss...
With the memory @ 250 Mhz @ 2-2-2, 1T, 200 divider, I got the following graph:
EDIT - Yellow line shows 2GB OCZ @ 213 Mhz.
As you can see, a clear relationship between tREF and errors, and a slight reduction in bandwidth @ low tREFs.
My questions are:
Is the ideal tREF specific to the RAM?
Is it specific to the memclock?
Is it specific to the divider?
From previous discussions, I'm quite a fan of the following:
ideal tREF = refresh rate / (1/clockspeed)
The problem is that there is so much mis-information about tREF about, and that table showing tREFs grouped into refresh rates (3.9, 7.8, 15.6 us) and clockspeeds (100 - 200 Mhz) only confuses things. Don't even get me started on Dracula's tREF tables .
Does anyone have any simple theory on tREF?
At least Dracula's four best and four worst tREFs bear some resemblance to my findings:
Four best =
* 1560
* 3072
* 3120
* 4708
Four worst =
* 0016
* 0032
* 0064
* 0128
My four best (1GB BH5) =
* 3684
* 3072
* 4708
* 4196
EDIT - My four best (2GB OCZ) =
* 2336
* 2048
* 2560
* 1536
I can only assume higher tREF = better, but knowing that the memory must be refreshed to keep the data 'alive', a higher tREF could also result in data loss...
Last edited:
