Ram

[A2C]

prosim vas ma niekto chut mi vysvetlovat to casovanie pamati ako tym myslym 2-3-5-7 ? :8O:

[Jerry]

A co takto pouzit google a pozriet si nejake dobre navody a recenzie?

[A2C]

no budem to musiet skust ak mi to niekto nevysveli tu ale dik ale neviem ani ako by som to mal hladat tak som sa rozhodol vyuzit tuto cestu ak to sem nepatri tak to kludne zmazte

[Toman]

no su to v podstate len take ciselka, pre normalneho cloveka nema zmysel riesit co ktore znamena, obecne plati ze cim mensie tym rychlejsie.

- asi najsledovanejsim je CAS access time (pristupova doba - rata sa v cykloch)
- je to to prve cislo, pri extremne rychlich pametiach je 2 pri strednych 2,5 a pri normalnich 3.
- tie hodnoty obycajne bios nastavy sam, ak netaktujes, a nie si posadnuty dosahovanim rekordou nema to velky zmysel menit...... (pouziva sa to pri pretaktovavani ked treba pamet zrychlit alebo spomalit)

velke mnozstvo chyb a hrubiek fixed by Jerry

[A2C]

Dakujem za odpoved a tie dalsie cisielka? to uz som pochopil ze
2-*-*-* velmi rychla pamat
2,5-*-*-* stredne rychla
3--*-*-* je najpomalsia ale co tie cisielka co su pod hviezdickami?

[AjsTi]

Len take cisielka maju svoj zmisel. Ale ako pise majster N.
Dovolim sem Ti pastnut nieco , co sa objavilo na jednom webe , na ktory chodim celkom casto. Je to sice v angline , ale myslim ze to by nemalo vadit. Jedna sa o nastavenie pameti na boardoch Abit konkretne s chipsetom ATI. Myslim , ze by to mohlo kus Ti pomoct. Apropo o pametiach je aj na sk/cz forach pisane i o konkretnom nastaveni a co ktore znamena.

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ABIT BIOS DRAM Settings Guide v.01 for the ABIT Forums:
(Forum Mods: feel free to sticky this or cross post it in other areas of the forums)

This guide is to help people figure out the confusing and unexplained DRAM BIOS options in their ABIT BIOS. If you see anything that is incorrect or needs clarification please let me know and I’ll update it here. If you change your timings and find your system will not boot in most circumstances clearing your system CMOS settings will allow you to set things back to default and try again. If you have a bad memory module or powersupply changing your memory timings can exacerbate the issue causing further problems. ALWAYS TEST FOR STABILITY AFTER CHANGING YOUR MEMORY TIMINGS WITH A PROGRAM SUCH AS MEMTEST86; JUST BECAUSE YOUR SYSTEM BOOTS DOES NOT MEAN IT IS STABLE.

WARNING! This guide has been compiled by me from various different sites. While I attest that all the information is correct as far as I know I am not responsible for any damage to your equipment that may occur from you altering your DRAM settings. This information might not work for those of you overclocking your memory settings. Use this information at your own risk!

Credits and Acknowledgements:

I do not claim to be an expert in memory timings. I simply compiled this information from an amalgamation of various sites. Most of this information comes from Adrian Wong’s “The Definitive BIOS Optimization Guide” which you can find free and online here. In the process of writing this guide I found a posting on the DFI forums that compiled much of the pertinent information from Adrian Wong’s guide along with other sites which you can find here.

I have attempted to create as concise a guide as possible to get you up and running quickly on ABIT motherboards; particularly newer models such as the AT8. If you wish to know the whys and whats of all these settings check out those two wonderful resources.

Before you begin:

First, the most important thing to check before you alter any DRAM timing is to make sure your RAM is set at the proper voltage. Performance RAM usually runs at 2.7-2.8 volts. Most motherboards (including ABIT) run DRAM voltage at the stock 2.6 volts by default. Your RAM may not perform to its specs if it is running under voltage. Go to your uguru settings and change the DRAM voltage to the manufacturer's recommended voltage for your memory. Once that is done…

For the purposes of this guide I will use the timings of my system RAM as an example (2g - 2 x 1g Corsair DDR400 PC Twinx 2048-3200 c2).

The memory timings of my RAM are 2 – 3 – 3 – 6 – 1T @ 2.75v:

Let’s first break down what each number means along as give it its industry abbreviation. (Note that many BIOS’s may call these settings by a slightly different name but the abbreviations will always be the same. For the purposes of this guide I’ll be using the names used in my ABIT AT8 BIOS v1.1)

2 CAS Latency Time (tCL)
-
3 RAS Precharge Time (tRP)
-
3 RAS to CAS Delay (tRCD)
-
6 Min. RAS Active Time (tRAS)
-
1T DRAM Command Rate

Right there you have most of the numbers to plug into your BIOS. There are three values left in regards to memory timings. The first is:

Row Cycle Time (tRC)
The simple formula for finding your (tRC) is: Min. RAS Active Time (tRAS) + RAS Precharge Time (tRP) = Row Cycle Time (tRC)

So using my memory timings:

(tRAS) 6 + (tRP) 3 = (tRC) 9

Next we have:

Row Refresh Cycle Time (tRFC)
The formula for (tRFC) is easily found after you get your value for Row Cycle Time (tRC). It is: Row Cycle Time (tRC) + 2 = Row Refresh Cycle Time (tRFC)

Using my timings again you get:

(tRC) 9 + 2 = (tRFC) 11

If you check the possible values for (tRFC) in the BIOS you will notice they are exactly the same as (tRC) only the values are increased by two.

Finally we have:

RAS to RAS Delay (tRRD)

This is pretty simple: If your RAM can handle it set it to two for faster reads and writes. If it can’t handle it set it to three for better stability. Quality performance RAM running at spec should handle the faster timing just fine.

Next we go into latency values:

Write Recovery Time (tWR)

Write to Read Delay (tWTR)

Read to Write Delay (tRTW)

Essentially the thing to know here is the lower the value the better the performance. My ram handles the lowest settings to all of these settings just fine but if you are overclocking or using value bargain RAM you might need to raise these settings for stability.

Finally we finish up with miscellaneous settings:

DRAM Command Rate (CRC):

1T for best performance – 2T for best stability. Go with 1T when at all possible.

Bank Interleaving

Enabled for best performance.

Burst Length

8 Way for best performance if your RAM can handle it. Essentially the larger the number the more your RAM can do in one burst.


Looking at the DRAM Memory settings page in the AT8 BIOS the settings for 2-3-3-6-1t RAM with the best possible timings running at spec would look like this:

DRAM Clock: DDR400
CAS Latency Time: 2.0 (tCL)
Row Cycle Time: 9 (tRC)
Row Refresh Cycle Time: 11 (tRFC)
Min. RAS# Active Time: 6 (tRAS)
RAS# to CAS# Delay: 3 (tRCD)
RAS# Precharge Time: 3 (tRP)
RAS# to RAS# Delay: 2 (tRRD)
Write Recovery Time: 2 (tWR)
Write to Read Delay: 1 (tWTR)
Read to Write Delay: 1 (tRTW)
DRAM Command Rate: 1T (CRC)
Bank Interleaving: Enabled
Burst Length: 8 Way


There you have it. If you believe any information needs to be clarified or corrected please let me know and I will update the information. I hope this guide is useful to you in tightening up your memory timings.
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[Fester]

Ja chcem len podotknut ze hodnoty CAS 2, 2.5, 3 sa pouzivaju hlavne pri 400MHz DDR pamatiach. Pri DDR2 (533,667,800)MHz su tieto cisla vacsie. Zalezi potom od kvality RAM ako sa daju nastavit.
napr. DDR2 800MHz ma casovanie 6-6-6-15 . Nie vzdy vsak plati, ze cim nizsie hodnoty tym vacsi vykon. Treba testovat a skusat.

[crux2005]

vysvetlenie casovania u DDR : http://www.pretaktovanie.sk/modules.php ... 688253&p=2

[A2C]

Dakujem velmi pekne za odpovede konecne tomu uz aspon trocha rozumiem dakujem