Topic: DDR 500 MHZ backward compatible?  (Read 6845 times)

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Towelie

  • Guest
DDR 500 MHZ backward compatible?
« Reply #20 on: March 17, 2004, 10:38:07 am »
  Okay, I am putting my new computer together, and I almost have the final pieces. I am going from a dual PIII 1.1 Ghz to a P4 3.2 Ghz with hyperthreading. I am browsing local memory and found this...

 http://www.circuitcity.com/detail.jsp?c=1&b=g&catoid=-10263&qp=0329832044200&oid=87385

...and was wondering if it was compatible. I know with some memory you can go faster modules than the bus. The FSB speed is 800mhz on this new MB.  http://www.matsonic.com/ms9377c.htm

  Is this RAM acceptable or should I go with DDR400 instead?
   

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #21 on: March 17, 2004, 10:40:20 am »
I havent heard much about it personally, so I couldnt tell you...

It must be in demand if its on the market heh...

Are there any reviews?

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #22 on: March 17, 2004, 10:40:44 am »
Depends really. If you're going to overclock the CPU, then go for it. If you aren't, then go with DDR400 modules.

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #23 on: March 17, 2004, 10:44:39 am »
How much would you have to OC the CPU to take advantage of it?

And would the FSB have to be CPU based?

Towelie

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #24 on: March 17, 2004, 10:45:05 am »
 Na, no overclocking. Just wondering since I can get it easier and faster than the DDR400 since it is on the shelves and the other has to be ordered (sigh).

Towelie

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #25 on: March 17, 2004, 10:45:43 am »
  FSB is 800 MHZ  

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #26 on: March 17, 2004, 10:48:34 am »
Well the FSB on my next machine is 1400Mhz :P

Sirgod

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #27 on: March 17, 2004, 11:01:12 am »
I think your ok with It towlie, but just in case, I'd check on the return policy.

stephen

Elvis

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #28 on: March 17, 2004, 11:10:55 am »
You could take advantage of the speed if you were overclocking, but there is no harm in underutilizing the RAM. So yes it is backward compatible: it will just act like DDR400.  

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #29 on: March 17, 2004, 11:51:23 am »
Quote:

  FSB is 800 MHZ  




Yeah, quad-pumped 200 mhz. So DDR400 would be the matching ram for it.


EDIT - if you think you may want to try a mild overclock in the future, then I'd buy either ram rated higher than DDR400, or very good DDR400 that will overclock without failing. My DDR400 in this computer clocked up to DDR450 before I switched to a 64-bit chip (only running it at 415 now)

EDIT2 - a lot of people on AMDMB's forum (http://forums.amdmb.com) recommend NewEgg (www.newegg.com) for computer parts in the US. They have a wide range and a good returns policy as well, if the ram is DOA.
« Last Edit: March 17, 2004, 11:57:02 am by James_Smith »

Lurker

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #30 on: March 17, 2004, 12:50:29 pm »
Don't know a great deal about P4 systems. Some motherboards allow you to set the speed of your memory as a percentage of your FSB. For example my system uses a 333Mhz processor but I have 400Mhz memory so I could set memory percentage as 120% of FSB, (I don't for stability reasons). I guess if your system was running at 800Mhz FSB and your memory is 500Mhz you'd need to set the percentage at 62.5, (assuming your BIOS has this option), or higher if you wanted to overclock the memory, (and Kingston make good quality overclockable sticks), but to be frank you would be better of setting this option to "by SPD" which automatically detects the speed of your memory and adjusts accordingly.

As I said, I don't know much about P4 systems so you might want to check your motherboard manual.  

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #31 on: March 17, 2004, 01:48:05 pm »
Quote:

I guess if your system was running at 800Mhz FSB and your memory is 500Mhz you'd need to set the percentage at 62.5




It doesn't work like that. An 800mhz FSB on a P4 doesn't require 800mhz ram to be in sync. 400 mhz would be in sync with it.

DDR400 is ram that runs at 200mhz but does work on both the rise and fall of the clock, so it's effective speed is 400mhz. Intel takes the 200mhz bus and multiplies it by 4, so the memory controller works at 800mhz. Hence the creation of dual channel DDR so the bandwith requirement can be satisfied.

As a side note, I hate Intel architecture. They excel in repetitive tasks, but need obscene clock speed compared to an AMD in order to compete at anything complicated. Hence we have the ridiculous situation where my friend's new 3.0ghz P4 is actually slower than my 2.0 ghz AMD64-3200+.

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #32 on: March 17, 2004, 01:49:46 pm »
What do you think about the FX-51?

Would DDR500 be better than DDR400 with it?

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #33 on: March 17, 2004, 01:55:24 pm »
Quote:

What do you think about the FX-51?

Would DDR500 be better than DDR400 with it?  





Mmmmmm FX-51..............<drool>

<wipes chin>

Sorry 'bout that. Got lost for a second. The FX-51 is a very very very veee-eee--eery nice chip. Problems are:

a) its mega expensive
b) it requires ECC registered RAM modules

I wouldn't bother with DDR500 tbh, if you want faster-than-400 ram then DDR433 should suffice. Plus, it usually has lower latency than DDR500 - and low latency is always best.

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #34 on: March 17, 2004, 01:58:25 pm »
I'll keep that in mind...

I dun spose you have an opinion on SATA RAID 1 vs IDE RAID 1 vs SCSI RAID 1?

jualdeaux

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #35 on: March 17, 2004, 02:04:00 pm »
Just out of curiosity, what is the FX-51?

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #36 on: March 17, 2004, 02:05:54 pm »
Quote:

Just out of curiosity, what is the FX-51?  




The mega-spec AMD 64-bit chip. 2.2ghz, and faster than pretty much anything Intel can bring to the party in a lot of situations.

EDIT - Sorry Active, nearly missed your question. My personal preference is SCSI over IDE. Not actually had any experience with SATA yet, but will be trying it in the future.
« Last Edit: March 17, 2004, 02:07:30 pm by James_Smith »

ActiveX

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #37 on: March 17, 2004, 02:13:17 pm »
SATA has bad reviews, maybe its just not settled yet heh...

I was goin to go with SCSI, but couldnt find any decent large capacity drives in SCSI...

So I'll prolly stick with the venerable IDE...

Lurker

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #38 on: March 17, 2004, 05:01:34 pm »
Quote:

Quote:

I guess if your system was running at 800Mhz FSB and your memory is 500Mhz you'd need to set the percentage at 62.5




It doesn't work like that. An 800mhz FSB on a P4 doesn't require 800mhz ram to be in sync. 400 mhz would be in sync with it.

DDR400 is ram that runs at 200mhz but does work on both the rise and fall of the clock, so it's effective speed is 400mhz. Intel takes the 200mhz bus and multiplies it by 4, so the memory controller works at 800mhz. Hence the creation of dual channel DDR so the bandwith requirement can be satisfied.

As a side note, I hate Intel architecture. They excel in repetitive tasks, but need obscene clock speed compared to an AMD in order to compete at anything complicated. Hence we have the ridiculous situation where my friend's new 3.0ghz P4 is actually slower than my 2.0 ghz AMD64-3200+.  




Thanks James, I kind of suspect 800Mhz P4's were using some kind of dual dual data rate system. The thing is you can get AMD motherboards that use dual channel and they only run at 400Mhz. Does that mean they are even using dual channel properly at all?  

James_Smith

  • Guest
Re: DDR 500 MHZ backward compatible?
« Reply #39 on: March 17, 2004, 06:05:01 pm »
Quote:

Thanks James, I kind of suspect 800Mhz P4's were using some kind of dual dual data rate system. The thing is you can get AMD motherboards that use dual channel and they only run at 400Mhz. Does that mean they are even using dual channel properly at all?  




The dual channel works the same for both chip designs - but the Intel chips with the quad-bumped bus rather than double-bumped see a larger improvement in their overall performance. Dual channel does improve the performance of an AMD system, but it's much more noticeable on a P4.

The interesting part comes when you look at a P4 using dual channel vs. an AMD64 using single channel in 32-bit operations. The AMD has the memory controller on the cpu die, so latency is massively reduced. This actually makes up for most of the single channel disadvantage. The P4 does still have the edge over it in operations that thrive on memory bandwith though. The next round of AMD64 chips (Socket 939) will have a dual channel controller, it will be interesting to see how they stack up.