Faster than DDR400 memory?

[sjohnson_2006]

Lately ive seen alot about the faster-than-DDR 400 memory, that is still DDR.
I was wondering what the dealio is abot these and if i can run em on my system.

[StormPC]

What is your system?

Also, it sounds like your level of computer expertise is not so high, but I don't know you so I will assume you're serious about your thread.

DDR400 is what they call DDR SDRAM that has been programmed to have certain timings @ 400MHz (2x200) and is designed and tested to run at 400MHz with the specified timings. It is also referred to as PC3200.

Memory that has been programmed and tested at other speeds (for example 500MHz (2x250)...DDR500 or PC4000...all the same stuff) is what I assume you are talking about.

There are a couple of things you need to keep in mind when considering memory. The first is that just because a DIMM is rated at a higher bandwidth (PC4000 vs PC3200) that does not mean the higher bandwidth memory will perform better than the lower bandwidth DIMM. There are a few reasons why this is the case. First, the overall performance of a memory module has more to do with the quality and configuration of the actual devices (chips) used in the DIMMs than what speed they are detected at by SPD. Another reason is that some CPU/MBD combos like higher MHz more than tight timings, but some do not. Generally it's best to run most motherboards without a divider (although A64s always run their RAM ASYNC so with them it matters not) with the DDR running at the highest possible MHz and with the tightest possible timings. This is not always easy to achieve. There is usually a bottleneck in any system. For this reason (and more) you really need to learn as much as you can about your particular system.

Might be a good idea to poke around at some of the memory manufacturer's sites (like Corsair, Mushkin and OCZ) if you want to learn more.

If you tell us what you have and what you want to accomplish we can suggest DDR for you. Good luck.

[sjohnson_2006]

My system:
A64 3200+ skt. 754
Gigabyte k8nsnxp (nforce 3 250)
Corsair value Select 1024 mb, DDR 400 (Pc3200) one stick. (horrible timings)
All in wonder 9200 (not so great, to be upgraded soon) (definatly the bottleneck)

ok... on my system without running dividers i know that my memory runs at the same frequency as my processor (200, normal) and if i Oc my processor, my memory goes faster as well. I dont have slower emmeory so i dont know how lets say pc2700 work....since it wouldnt run at the same frequency as my processor right? So im guessing that if i bump up my processor from 200 to, lets say 210, then my memeory would also go up by 10 Mhtz.

So im guessing with memory like DDR500, since it runs at 250, which is faster than the processor, OC te processor by 10 would also OC the memory by 10?

SO on my computer can i take out my DIMM and put in a gigabyte of DDR500 and expect it to boot?

[StormPC]

It would probably boot because you have the timings so loose on your memory now, although depending on the memory it may not boot without clearing the BIOS. The question is, will it run 500MHz+ at any timings? The answer again is, it depends on the memory.

The thing is, DDR500 is not really made for your system which supports 400MHz max. That doesn't mean your motherboard can't run at 500MHz+, it just means it doesn't officially support DDR500. Also, 500MHz memory tends to be more expensive than 400MHz memory, although there are exceptions. Stay away from anything over 400MHz (PC3200). Most of the top overclockers in the world are running HIGH QUALITY PC3200 at tight timings. They are often times running at speeds much greater than 500MHz on their memory (like I said before, it's quality that counts not the bandwidth rating).

I can tell by your posts you have much to learn about overclocking. If you really want to get into overclocking you need to start reading A LOT!!!

For your rig I suggest 2 of the cheapest sticks of PC3200 with Samsung TCCD chips on it you can find.

Go here for a list: http://xtremesystems.org/forums/show...highlight=tccd

Make sure it will run 5-2-2-2 timings at stock volts (SPD programming...the reason you want PC3200 400MHz memory). Crank the DDR volts as high as your Gigabyte will go. Then slowly increase the FSB freq. Yes, if you raise the FSB 10 the memory raises 10x2 (DDR???) so at CPU 210x10 your CPU runs at 2100MHz and your memory at 210x2 or 420MHz (assuming it's set in the BIOS to run 400MHz 2:1 vs 333MHz 5:3. Also, A64s have no divider. The RAM is always running ASYNC. The 2:1 and 5:3 are actually multipliers. 2:1 = 2xCPU base freq, 5:3 = 1.6666667xCPU base, etc...

Hope this helps.

[Kumagoro]

Really you shouldnt say DDR400 MHz it should be 200 MHz and the bit rate is 400.

[sjohnson_2006]

1) My memory runs at 3-4-4-8 right now. Can I change the timings (SPD programming?), and if so what will this do to my stick, just make it run hotter?.

2) And you tell me to make sure the next DIMMS i buy will run at 5-2-2-2, the low latency corsair ram runs at 2-2-2-5, im assumming this would work. to those specs.

3)Also how can I know the max voltage my DIMM will go, if i raise it too high, wont it damage my memory chips?

4)BTW, the multiplier for my cpu is 11 so 210 x 11 = 2310, im assumming thats what you meant.

EDIT 5) Ive seen memory that lists timings such as, 2-3-3-6-1T, ive wondered what the 1T represents.

I appreciate all your help.

[StormPC]

Really you shouldnt say DDR400 MHz it should be 200 MHz and the bit rate is 400.

Well then nobody would understand WTF I was talking about. I didn't make up the DDR and memory (nor any other computer related) nomenclature, so what basis do you have for your claim that I "should say" this? Also bit rates are usually associated with serial data communications, not memory. My 128 bit memory controller is not serial.

DDR400 runs at 400MHz, not 200, just as a CPU that runs at 2000MHz is not said to run 200MHz at a 2000MHz bit rate just because it uses an internal multiplier of 10 to achieve it's clockrate. To make a long story short, you are not correct.

sjohnson_2006:

1) You can change the timings your motherboard tries to use in the BIOS but that will not reprogram the DIMMs. You can't program them yourself. You need special equipment to do it.

2) The Corsair XL runs at 5-2-2-2 or 2-2-2-5 (same thing, just reversed the order of the timmings.)

3) No. Unmodded motherboards do not supply enough voltage to harm most DDR modules. Notice I said most. Your RAM can take at least 2.8v without voiding the warranty, and over 3v won't hurt it if in most cases. Keep it under 3 volts and you'll be fine. If you buy high performance memory (like the Corsair XL) they just start to wake up at 2.9-3.0 volts in most cases. If you run any memory over 3 volts you need to make sure your case cooling is very good. You may even want to active cool your RAM.

4) I was giving a general example and not your's specifically.

EDIT 5) 1T is the command rate. You really need to visit the Corsair site and do some reading. In general you want to run 1T whenever possible because running 2T will cause you to lose much bandwidth. The only reason you may want to run 2T is if your RAM is so crappy it can't keep up with the A64's memory controller. That's the only reason A64 boards now have the option to run 2T. All the original morherboards for A64 would only run 1T but that caused stability problems because people were just slapping any old DDR into their A64s and then wondering why it wasn't stable. Running at 2T you can basically use any old crappy RAM and still get a decent overclock out of your CPU.

[Kumagoro]

If you had studied electronics at uni then you would understand what the difference is.

The reason why some people say 400 MHz is because the concept had to be simplified
for the laymans out there. The internal freqency or clock speed is 200 MHz, data rate is 400 Mbps. Thats why normally people say 400 MHz is the "effective" clock speed so they could understand that it was better than SDR.

http://www.samsung.com/Products/Semi...y_cd=DRM030104

... was just trying to give proper terminology.

[StormPC]

Well I can only speak in terms that are used within the computer community. If they are not correct it's not my fault because it was not my idea to use flawed terminology.

What you (and Samsung) are saying is applicable to the semiconductors but they (and you) are mistaken to use semiconductor terminology to describe the features of the modules themselves. See, the data rate of the semiconductor makes no difference to the user. It's the speed of the modules that is important. I believe it is an error to confuse the data rate of a semiconductor with that of the module. While the data rate of the chip may be 400Mb/s that of the module is certainly not. Typical PC3200 (200MHz DDR400) is called PC3200 because the modules have a bandwidth of 3200MB/s (25,600Mb/s), not 50MB/s (400Mb/s) like the chart seems to suggest. I was speaking about memory modules, not chips.

I was probably an Electronics Engineer before you were born. I appreciate you trying to give proper terminology but you have a lot to learn. You're getting bogged down in semantics really. I'm sure even with my flawed terminology you understood what I was saying.

Layman? Just kidding...

Cheers!

[Kumagoro]

What you wrote before your edit was wrong. So what i was going to write isnt applicable.

Either way modules or dimms run off a 200 MHz clock, data is transfered on the rising and falling edge of this clock which gives an effective clock speed of dun dun daaaa 400 MHz. This is not the clock speed it is the data rate, access rate and many other names BUT NOT the bandwidth they are different things. It just means memory can be accessed/transferred, read etc on the rising and falling edges, the bandwidth comes from pulling data from memory addresses, ala 8 bytes. so 400 * 8 bits is 3200.
(Should read 8 bytes not bits)
The simplist model i can think of, do you get it?

[Kumagoro]

By the way im not trying to insult you, just get rid of some old terminology when it first came out which still hangs around even on manuf sites because its what people now know it as even on the samsung site. I feel that now SDR is gone that the real clock freq (what the transistors switch at) should be quoted and the bandwidth. Not this inbetween value. It could get worse with ddr2 which is able to transfer 4 times per clock cycle i think.... People, well most people on here at least, understand that a AMD64 is better than a P4 clock for clock as more things can be done per clock cycle. They dont do a calculation of freqency based on the effective freq exactly do they its more compared to the P4 isnt it or did they change it to what the original athlon would do at that speed... its all bollocks really isnt it on mobos some say 200 MHz and some say 400 MHz... perhaps it would be better if they quote the theoretical bandwidth with it.

[StormPC]

Wrong again. PC3200 (not all DDR) are designed to run off a 200MHz clock. What they actually run depends on the platform they are installed on and the base clock fed to them by the motherboard (or CPU, in the case of A64s) which can vary greatly. I run my Corsair XL PC3200 w/Samsung TCCD chips on an A64 at 320MHz (base HTT/CPU freq) x 5:3 or 1.6666667 (533MHz effective or PC4200 speeds). BTW: It's called PC4200 because the bandwidth is 4200MB/s. That's Megabytes, not megabits and it's not derived by multiplying 200 (or 266) x 2 x 8 bits. So I guess your model only works for DDR400? It would have made more sense if you said PC3200 has a nominal bandwidth of 3200MB/s because the modules have a data transfer rate of 400 bps per data line and 64 lines (because they are 64 bit memory). 400Mbp/s=50MBp/s x 64 lines = 3200MB/s, because this is the case.

Do YOU get it?

I don't understand what any of this has to do with my post or the topic of this thread. If you do please enlighten me.

I'm not trying to insult you either so that's good!

[Kumagoro]

If you pay close attention 64 lines is the 8 bytes i stated above, the mistake is the writing bits instead of bytes but before that i state bytes... it seems you cant tell that basically you did the same calculation in exactly the same way but just converting to bytes for the data rate and then bits for the memory... i.e the lines....

so tell me how do you get a bandwidth of 3200 MB/s when not running at 200 MHz using standard DDR and optimal settings?

Its to do with the OP as he correctly states it as DDR400 and not with MHz, which is incorrect.

[StormPC]

I think we've taken this thread in this direction long enough. Actually, I believe this thread has outlived it's usefulness. Let's let it die, shall we?

[sjohnson_2006]

yeah, ok well thats ok if you want to let my thread die....but just one last question.

So if i go into my BIOS and change my memory from 3-4-4-8 to 2.5-4-4-7 (just an example), what would this accomplish if I cant REALLY change the latencies of my actual memory?

[Stewart]

Also, it sounds like your level of computer expertise is not so high.

So what better place to come than HEXUS?

Well helped Storm, my man. Keep it up. Show us those world records you got for being a l33t overcl0cker were not wasted.