DDR2 Memory Speeds Explained - Page 5 - Overclock.net

Notorious · 04-03-09

Hmm I see, and since the CPU is an AM3 socket, it will also work with a AM2+ board with support up to DDR2-1066, and above that for AM3 board which usually supports DDR3, I heard some even support both DDR2 and DDR3.

Not really sure if I would go for AM3 and DDR3 yet, but sounds like somethin i have to dive in for future proof reasons. And then comes DDR3-1333, 1600, more headache I guess haha. So mainly I would stick to AM2+ board and DDR2 still, depends on the price of AM3 board and DDR3 tough.

There's a X3 720 BE club here, looks like the overclock is the same as the previous Black Edition, just adjust the multiplier heh, you can see some examples on their overclocking results.

http://www.overclock.net/amd-cpus/47...x3-720-oc.html

As you can see some use half multiplier numbrs like 18.5, 16.5, hmm seems to work fine heh.

Dudeson169 · 04-12-09

thank you for this guide, helped me alot to see why my ram was being underclock3d

durch · 04-13-09

I hate how rep is anonymous, to the person who left this message:

Quote:

Good guide. But HTT is Intel's Hyper Threading you want HT. Look it up? Good work I did not know all this.

No I don't want HT, I want reference clock. HTT is indeed Intel's hyper threading and is an incorrect term for AMD's reference clock. However, AMD never established a name for the reference clock, and because of that motherboards call that value all sorts of things that are incorrect like CPU Frequency and HTT. Many people confuse the reference clock with the HT Link, and at the time of writing the original post, HTT was by far the most widely used term on OCN to refer to the reference clock and HT was used for the HT Link. Many people used HTT to refer to BOTH the reference clock and the HT Link. Needless to say there was always confusion when people tried helping with overclocks. In fact I hadn't seen a single post where anyone called it the reference clock. Since the point of this post was to help people, I originally used HTT not reference clock so OCN users would understand what I was talking about.

It wasn't until I wrote my overclocking guide that I attempted to get people to use reference clock and HT Link to help clear up future confusion. I saw the term reference clock used on another web site and the term made the most sense to me, as the CPU frequency and HT Link reference it to calculate their speed. I decided to use this more proper term in my AMD Socket AM2 Overclocking Guide that I wrote 6 months after writing this guide. Since my overclocking guide references this thread, I switched HTT to reference clock in the original post and added an edit that explains that the first few responses will use HTT to refer to the reference clock. I did not edit the early responses that use HTT because the posters asking the questions used HTT and I wanted my answers to their questions to match up to avoid confusion.

And there was no need for the sarcastic "look it up?"

I'm well aware

But thank you for the rep

I dunno why people called it HTT, they were calling it that well before I joined. HyperTransport Technology maybe? Similar to the "technology" of HyperThreading Technology? I dunno, you'd have to ask them.

From my overclocking guide:

Quote:

Reference Clock
This is the setting that starts at 200 and is increased to overclock your computer. This is the single most important setting, as the CPU, HT Link and memory all reference this number when calculating their speed. The reference clock is often incorrectly referred to as the FSB, which is an Intel term that has no bearing on AMD 64 X2 systems. The reference clock is also referred to as the HT, HTT, CPU speed, and many other terms that aren’t really correct, however many people and motherboards use them. It is important to note that unlike Intel’s FSB, no data is actually transferred on the reference clock. It is merely a number created by the clock generator that other devices reference to calculate their speed. Your motherboard should give you the option to increase the reference clock by any whole number, up to a certain max value such as 400 (i.e. Auto, 200, 201, 202, 203, …, 398, 399, 400). It is usually a bad idea to increase the reference clock by any more than 10MHz at a time, as large changes can cause your system to fail to post.

Slink · 04-13-09

Yet again, a wealth of information--much of which I was unaware. Thx!

Sandman8709 · 04-22-09

Ehh this kinda makes since but it hurts my head.

durch · 04-22-09

Quote:

Originally Posted by Sandman8709

Ehh this kinda makes since but it hurts my head.

Haha, well if you provide the specifics of your system and your goals I can help you work out the possible RAM and CPU speeds.

What's important is:
1) the max CPU multiplier available to you
2) the highest stable CPU clock you've achieved with reasonable load temps (load temps below 60*C, stable meaning it passes several hours of an Orthos small FFT test and several hours of an Orthos blend test)
3) The speed, timings and voltage of your RAM (i.e. DDR2 800 rated for 4-4-4-12 timings at 2.1v)
4) Any info on RAM testing you've done, if you've done any

Get back to us with that and we can help you get the most out of your memory.

EDIT: I'll be away from a computer for 3 days starting tomorrow.

Slink · 04-23-09

Durch is among the most helpful, if not the best help with overclocking DDR2 RAM on an AMD motherboard, but there are many others here who can help you as well (including me). I learned (mostly from Durch) how to OC DDR2 on AMD boards.

It always helps if you have a digital camera to take pictures of your BIOS/CMOS setup screens!

Good luck, and have fun! (GLHF)

Let us know if you need help.

goodolsen · 06-26-09

I just found this thread and I'm hoping its still monitored. I'm looking for some help getting the best out of my system.

I'm running an X2 4800+ (stock settings 200 x 12.5 for 2.5GHz) Right now I've got it set to 240x 12.5 running at 3.0GHz. It's showing my RAM is running at 428.3. I'm using Transcend DDR2-800 w/5-5-5-18-2T timings.

This is the link to my CPU-Z validation. http://valid.canardpc.com/show_oc.php?id=583368

My question is this, have I done a good job OC'ing my machine, or are there things I can do better to get the most out of my CPU and RAM? Would changing the multiplier to 12 and the Bus to 250 be better? Should I try changing the timings on my RAM?

Any feedback is appreciated.

-goodolsen

durch · 06-26-09

Hey goodolsen,

Looks to me like a pretty good overclock. The older X2 4800+ probably won't go much past 3.0GHz (your current clock) if at all, but CPU speed is far more important than memory speed so if you want more performance, trying to push your CPU further is the place to start. If that's the highest stable CPU speed you can reach, then the only other thing to try is to lower your CPU--> Memory divider to increase your RAM speed, or to tighten timings at your current speed.

AMD AM2 systems don't see much benefit from RAM speeds over 800MHz, they are usually a little more responsive to changes in RAM timings. So my recommendation is to try tightening your timings a bit. But if they're rated for 5-5-5-18 at 800MHz and you're currently at 857MHz, I doubt you'll get to 4-4-4-15, but you might be able to tighten a few a little.

You can lower your CPU --> Memory divider (currently at 7) to 6 by changing your CPU multiplier to 12x instead of 12.5x. Increase your reference clock from it's current 240MHz to 250MHz to re-establish the 3.0GHz CPU speed. At this same CPU speed but new divider of 6, you'll be running your RAM at 1000MHz up from 857MHz. A big jump, so your RAM might not be able to handle it. But if it can, it should give you a small boost in performance.

Good luck, let us know how it goes.

goodolsen · 06-29-09

Well after some playing around with settings, I actually lowered the CPU speed from 3.0 to 2.8GHz so that its more synch'ed with the RAM. Since I don't have high quality RAM, I didn't want to push it too far.

Also the CPU was running about 115-125 F, and with it being a Texas summer in triple digits I figured lowering the speed wouldn't be a bad idea.

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