Easy as 1, 2, 3, Overclocking the A64, Opteron, X2

[Setsukos]

This has probably been mentioned but that AMD A64 Calculator that is linked has a RAM forumula fault. Or have I missed something???

When it cuts the CPU multiplier in half it doesnt round up to a whole integer...

Originally Posted by QuietIce
One more note - the DDR2 MemClock runs slightly less than 400 (at stock) on odd CPU multipliers. The reason is the formula for calculating the actual MemClock, which is (CPU speed/MemDivider). The MemDivider for DDR2 (at 1:1) is half the CPU multiplier but must always be an integer and rounded up. So the MemDivider for an x13 CPU is 13/2=7, therefore a CPU running 2600 MHz (200x13) will only have MemClock of (2600/7) ~371 MHz, which doubles to DDR2-743 instead of DDR2-800 ...

Example what it says:
2250MHz
250 HTT
x 9
1000 HT Link
208 Ram Speed (DDR2-832) << 9/2=4.5 = 2250/4.5 = 500*.83= 415 (thus 208 and 832)

Should be:
2250MHz
250 HTT
x 9
1000 HT Link
186 Ram Speed (DDR2-747) << 9/2=4.5 should be 5 = 2250/5 = 450*.83= 374 (thus 186 and 747)

 

[QuietIce]

Although the A64 calculator in post #1 is slightly off it's not exactly for the reason you've listed.


I assume you're using the "*.83" to reflect a DDR-333 RAM limiter? Note it is DDR-333, not DDR2-667. This makes a huge difference in the calculations. For DDR you divide the CPU multiplier (x9) by the RAM limiter (in this case 5/6) to get 54/5 = 11. 2250/11 = 205, which is a very slight difference from the 208 the calculator gives you and plenty close enough for a rough calculation.

With DDR2 you do the same thing but take an extra step and divide by 2 before rounding. So for our example we have 54/5*1/2 = 54/10 = 6. Now we have 2250/6 = 375, not the 416 you get by simply doubling the calculated DDR speed shown for DDR-333 ...

 

[rx7fd3s]

Oh btw! How do i start setting memory all these?
issit thru BIOS?
I have nvidia cotrol panel... it can adjust motherboard too, but i'm not sure.
So wanna double check.

Cheers~~~

 

[bradyapba]

ok, im using clockgen, and i noticed its also increasing the PCI frequency.... is that a problem, or no big deal?

Thanks.

 

[QuietIce]

to both of you!

Oh btw! How do i start setting memory all these?
issit thru BIOS?
I have nvidia cotrol panel... it can adjust motherboard too, but i'm not sure.
So wanna double check.

Cheers~~~

Better to OC through the BIOS.

ok, im using clockgen, and i noticed its also increasing the PCI frequency.... is that a problem, or no big deal?

Thanks.

You've got problems! (and probably a VIA chipset).

<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>

If either of you need more help please start a new thread in the appropriate motherboard section. You'll find more people to help you there and better help as well, since we all frequent the forums of the hardware we know ...

 

[Swedishfrog]

athlon 4600 overclocking rig

Hi,
Very interesting OC advice - excited to OC my system with what I have.

Currently, stable:Win Leopard XP SP3...

Asus A8N32Sli-Deluxe 939pin mainboard
Athlon X2 4600+ E4 @ 1.34 vcore, 2.65Ghz (12x221) + Arctic Silver 5;
Corsair XMS TwinX 2048C2 PC3200 @ DDR443-3-3-3-7-1T,2.85v (221/216 Limit)


Cooling:
Thermalright Si-120 + Silenx Pro 120x38mm 90cfm Copper HS-pipe;
OCZ XTC DDR cooler (twin 60mm fans)
Antec SQE7000 chassis + 4x130x25mm
Asus copper heatpipe NB-SB-MOSFET
PSU top twin-fan only - intake from mainboard.

(new chassis transplant: CM-690 = 3x120 exhaust + 5x120mm intake + 80x15mm under-CPU intake; PSU twin-fan bottom in-and-out vents)

 

[AKruZer]

3 years on and this post still rocks.

 

[splat]

at the same time it's kinda sad that it took AMD so long to get new chips out, and the new chips aren't worth using yet.

 

[Bangwhiz]

Confused on Step 1 - please straighten me out

For Step 1 guide says:

"If your motherboard is supported by clockgen you can speed up this process using the following method.

Set your CPU to a low multiplier (6x), memory to a low divider (133) and your HTT to 5x. Boot into windows and start up clockgen. While running either prime95, superpi 32m or some other stress testing program increment the FSB by 5MHz. Let the stress testing program run for around 5 minutes or so and then increase the FSB by another 5MHz. Repeat this process with your HTT multiplier set to 3x and record both numbers."

Do you keep increasing the FSB using clockgen 5Mhz until Prime95 fails, or do you just bump 5Mhz twice at HTT at 5x - then record a number and then repeat the test with 2 5Mhz bumps at 3X and record the number?

Probably ridiculous question, but trying to make sure I do this step right.

 

[QuietIce]

to OCF!!!

Things have changed a little since that was written. In the end you really don't want to run it much past 1000 MHz anyway but it's still good to check your HTT speed to make sure it'll support ~1100.

To check the HTT limits you leave it at 5x until failure. If it makes it to 1200 w/out failure call it a day and move on to the next step.

Start a thread in the AMD motherboard or CPU section if you'd like - lots of people will but in their 2 cents there ...!

 

[Bangwhiz]

Now I'm really confused. Is this sticky out of date for AMD X2 4200+?

 

[harlam357]

This sticky was written with socket 939 hardware in mind... so if you're running an AM2 K8 with DDR2 things are a little different in the memory department, RAM dividers are on a different scale.

And if someone is running an AM2+ with Phenom then things change quite a bit more... I wouldn't recommend this as a guide to overclocking Phenom.

 

[MrSeanKon]

harlam357 as we all know things change rapidly especially with PCs.
As about the new AMD platforms the RAM overclocking process differs enough than 939 socket.

 

[JimOkc]

Thank you for the guide. It was very clear and made learning to OC very fun and easy.

JimOkc

 

[antique222]

why i can't go more than 2450 mhz :| ?please tell me.My system is :
CPU: AMD Athlon 64 2800+ @1800 Mhz(200x9)(FSB 200mhz ,HTT 800Mhz (x4)
Motherboard : Epox Nforce 3 250 Gb
RAM:1 Gb ddr400 Geil 2.5-3-3-6@200mhz
512 ddr400 Twinmos 2.5-3-3-8@200mhz
Video: ATi RAdeon 9600XT 256 Mb/128 bits (gpu:500 mhz; memory:600mhz)
Power Supply 400W
HDD :WDC 120Gb

With OC,the system is runing at: 2400Mhz\HTT x3\ram at 166,1T\Fsb 270\

Please Tell me how far i can go? and why i can't go ?the problem is the RAM ?amd or motherboard?

 

[splat]

why i can't go more than 2450 mhz :| ?please tell me.My system is :
CPU: AMD Athlon 64 2800+ @1800 Mhz(200x9)(FSB 200mhz ,HTT 800Mhz (x4)
Motherboard : Epox Nforce 3 250 Gb
RAM:1 Gb ddr400 Geil 2.5-3-3-6@200mhz
512 ddr400 Twinmos 2.5-3-3-8@200mhz
Video: ATi RAdeon 9600XT 256 Mb/128 bits (gpu:500 mhz; memory:600mhz)
Power Supply 400W
HDD :WDC 120Gb

With OC,the system is runing at: 2400Mhz\HTT x3\ram at 166,1T\Fsb 270\

Please Tell me how far i can go? and why i can't go ?the problem is the RAM ?amd or motherboard?

first question is: exactly what type of psu do you have? 2nd question is: have you tried running one stick of ram at a time? The miss-matched ram might not play nice. 3rd: have you followed every step of the guide and written down the limits for each component, i.e. ram max, cpu max, HTT max?

 

[antique222]

i've tried running one stick at a time and with geil was running at 2550 and with twinmos at 2400. I don't write the limits i'll try .Thanks

 

[milo0911]

I've been looking for a post like this forever! Nice good way to start your overclocking...then to use the rest of the stickys and members to fine tune! Good Job! *Bump*

 

[QuietIce]

If you'rew OC'ing an AM2 you might want to check out the update ...
http://www.ocforums.com/showthread.php?t=555058

 

[cold.nut]

So far so good!

Amd Athlon 64 x2 6000 + currently at a stable 240 x5 HT (1200mhz), looking to get this puppy OC'ed real good by school on Monday

Hope for the best I guess!