# Understanding DDR RAM timings/settings (to overclock)



## Rollercoaster (Nov 4, 2005)

Guys i have a config of::
Athlon64 3000+ 
ASUS A8N SLI Prem
Hynex HY5DU121622CTP-D43 DDR400 512MBx2 RAM
XFX 6600GT 256MB PCIe
Segate 7.2K Barracuda 160GBx2 on Silicon RAID0
Odyssey-JULY05 500w 20PIN ATX PSU


Below is a list of the exact DRAM config page from my MObos BIOS setup.
I want to know the exact meaning of each of the following items.

DRAM Configuration

*ITEM RANGE DEFAULT(for my RAM)*
Memclock index value (Mhz) 200-600   400
CAS# latency (Tcl)  2,2.5,3     3
Min RAS# ative time(Tras)  5T-15T     8T
RAS# to CAS# delay(Trcd) 2T-7T		4T
Row Percharge Time(Trp) 2T-7T		4T
Row cycle time(Trc) 7T-22T		11T
Row refresh cyc time(Trfc) 9T-24T		14T
Read-to-Write time(Trwt) 1T-6T		5T
Write Recovery time(Twr) 2T,3T		3T
1T/2T Memory Timing	 1T,2T		2T

Also i want to know how to identify the above values for RAM Modules without plugging them in (the default values) either from the model no. or any other info.

Then finally i want to know how to correctly overclock by modifying the above values.

If u could point me to some literature in the net then it would be fine too.

I am familier with CPU overclocking.

Is my RAM any good? and if not how and which RAM to buy (should not be too costly)
The above ram i bought for 2500Rs each, 20 days ago along with all the above mentioned hardware.

Thankx in advance...(Anyways how to be put in tabs in this post???)


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## siriusb (Nov 4, 2005)

> Also i want to know how to identify the above values for RAM Modules without plugging them in (the default values) either from the model no. or any other info.


PDF: How to identify hynix module

Here's some literature that you might help you with the other questions:
A Guide to Memory Timing
"THE" Definitive DFI AMD Overclocking


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## Rollercoaster (Nov 4, 2005)

gotcha....


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## Rollercoaster (Nov 6, 2005)

Ya.. hey i have the OC cieling of my A643000+
it is 2675Mhz

Nw i have to find the cieling of my RAM...

But do u know how to read SPD JEDEC specs from the RAm module


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## siriusb (Nov 6, 2005)

I am not sure what you expect, but if u want to set the default values from the spd, just set the ram timings to auto.


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