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Guest PaulL01

Elrond,..need advice for faster memory please..

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Hi Elrond,What would you advise as per a memory upgrade for my Epox-8KHA+? Right now I am using a single genaric PC2100 256 stick and I beleive it is one of the limiting factors to higher FSB speeds.I do have a limitted budget but I dont know if there is such a thing as low cost "fast" memory. :-lolThanks as alwaysPaul

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Hi Paul,Sorry so late with the reply as I've returned to work (:-().Since your 8KHA+ is based on the KT266A and PC2100 is its official support, your existing PC2100 should fit the bill - assuming your existing generic memory has Micron or Samsung chips that is. You can always upgrade to higher end PC2100 at CL2 for a performance boost, but today that probably is not a good investment considering the current flux of the memory market and where its heading.What I think you're asking however, since you bring up the FSB speeds, is what memory would be optimal for overclocking your FSB above the official 266 Mhz. In that case, I can whole-heartedly recommend Corsair memory to you. If you don't mind spending cash on replacement memory when it may not be fully useful six months down the line, I'd recommend you go with Corsair CL2 memory at either PC2700 (CMX256A-2700C2 at around $90 US online per 256MB and also available in 512MB modules: CMX512A-2700C2) or PC3000 (CMX256A-3000C2 at around $115 US online per 256MB and also available in 512MB modules: CMX512A-3000C2).Since DDR333 is the new standard that is being pushed so hard, PC2700 (only accept it at CL2) should fit you fine for the possible future as well. If DDR400 is released this fall instead of the wait for DDR-II at 400Mhz next year, PC3000 might be a better bet (this is what I'd choose right now). While full DDR400 will mean PC3200 memory, there is no such beast on the market today at CL2 within mere mortal pricing. If you switch over to something like the KT400 in the next year however, you should easily be able to run the above PC3000 at PC3200 speeds - albeit with a possibility of running it at CL2.5 instead.On your existing motherboard, either memory should allow you to bump your FSB with relative ease compared to your existing PC2100.Hope that helps,http://members.rogers.com/eelvish/elrondlogo.gifhttp://members.rogers.com/eelvish/flyurl.gif

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Hi Elrond,I enjoyed the Anandtech review of P4 you directed me to last week. I am intrigued by your above comments (particularly since I didn't understand everything you said :-shy). Do you have a comparable review you can point me to that deals with memory, FSB speed, Bandwidth, and how they all tie together (or don't??).As always, thanks for your posts in this forum.

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Hi David,Hmmm. I can't think of one off hand that covers all the topics you wish to learn just now... I'll see if I can dig something up that fits the bill and link it here when I get home tonight.As a simplistic primer in the meantime, let me point out the different memory and bus speeds on the Athlon platform as discussed above:1) PC133 had been the memory standard for quite a few years. This memory has signal timings only once per memory clock cycle: hence its not DDR (Double Data Rate) and performs at the rated 133Mhz that its name implies. An example chipset is the VIA KT133.2) PC2100 (interchangeably called DDR266) is the most widely adopted standard since PC133. PC2100 runs at 133 real Mhz just like PC133, but this memory has signal timings twice per memory clock cycle (electronic speak: on the rising and falling edge of each cycle) giving it identical performance as if it were run at 266Mhz (hence the name of DDR266). It provides bandwidth up to 2.1 GB per second (hense its main name of PC2100). An example chipset is the VIA KT266A.3) PC2700 (interchangeably called DDR333) is the new standard being pushed at the moment. PC2700 runs at 166 real Mhz, but this memory is just like PC2100 in that it has signal timings twice per memory clock cycle giving it identical performance as if it were running at 333Mhz (hence the name of DDR333). It provides bandwidth up to 2.7 GB per second (hense its main name of PC2700). An example of a new chipset that supports this memory is the VIA KT333.4) PC3200 (interchangeable called DDR400) is a probable future standard to be introduced this fall. PC3200 runs at 200 real Mhz, but this memory is just like PC2100 in that it has signal timings twice per memory clock cycle giving it identical performance as if it were running at 400Mhz (hence the name DDR400). It provides bandwidth up to 3.2 GB per second (hense its main name of PC3200). A possible example of this future chipset that may support this memory is the proposed VIA KT400.5) There are other types of specialized limited quantity DDR memory available such as PC2400 and the like... These are not based on true standards, but are specialized high performance memory that has been manufactured for overclockers to push their FSB speeds higher than standardized memory would have allowed. PC3000 (interchangeably called DDR366) is one of these memory modules. PC3000 is spec'd to run at 183 real Mhz, but this memory is just like PC2100 in that it has signal timings twice per memory clock cycle giving it identical performance as if it were running at 366Mhz (hence the name DDR366). It provides bandwidth up to 3.0 GB per second (hense its main name of PC3000).Next year will see the introduction of DDR-II initially at 400Mhz. This is almost identical to DDR400, but it has been redesigned to stabilized the signal paths in such modules to allow future speed ratings higher than 400Mhz without problems (and to supposedly reduce costs). It may be that the industry bypasses DDR400 this fall and waits for DDR-II at 400Mhz next year - this is being highly debated right now. Samsung has already started mass production of DDR400 for this fall however.In addition to DDR memories, there are P4 only memory solutions available in the form of Rambus (RDRAM). I won't cover these for the time being however, since thats not what I was discussing above.So back to the Athlon platform. Since the Athlon's introduction three years ago(?), its CPU has had a limit of running on a 133 real Mhz bus, using DDR technology to boost the throughput to 266Mhz (as described above). Since there are now memory technologies out that run at higher than 133 real Mhz, there are new chipsets that allow the memory bus to run asynchronously to the CPU bus (meaning at different rates). With such chipsets like the KT333 running with PC2700 memory, the CPU bus still runs at 133Mhz (266Mhz DDR) and can take advantage of up to 2.1 GB/s bandwidth while the memory bus runs up to 166Mhz (333Mhz DDR) and can provide up to 2.7 GB/s of bandwidth. The problem with this as you might see is that the CPU can never take advantage of the extra bandwidth provided by the faster memory bus since data can only travel as fast as the slowest bus allows (in this case: 133 real Mhz or 266Mhz DDR with up to 2.1 GB/s bandwidth).A way to get around this limitation until an updated Athlon is released running on a 166Mhz or greater bus is to overclock the CPU bus to higher than 133Mhz. The CPU bus is whats referred to as the Front Side Bus (FSB). In Pauls case above, thats what he is wanting to do. Since his existing PC2100 memory was designed to run at the same 133 real Mhz (266Mhz DDR) as his CPU, he's having a bit of trouble pushing his FSB to the higher Mhz levels he thinks his CPU and motherboard can handle. Optimally, overclocking can allow the Athlon XP CPU to hit up to 200Mhz if the bios you run supports pushing the FSB that far. This is under optimal conditions remember and wholly depend upon just the right parts to achieve such a push. Also note that doing this may shorten the life of individual components, specially if proper cooling has not been provided. That being said, if he puts in PC2700 or PC3000 memory in his sytem, he can possibly have an easier time pushing his CPU FSB to the same levels the memory was designed to run at. And since PC3200 is a likely fall standard, I recommended to him PC3000 for the investment, since he could probably run that memory on the future KT400 as well (but possibly set to lower CL2.5 timings).Hopefully that somewhat clarifies some of the things I was talking about above. I'll see if I can dig up a few articles that will explain this much better than I have and will hopefully provide some benchmarks as well.Take care,http://members.rogers.com/eelvish/elrondlogo.gifhttp://members.rogers.com/eelvish/flyurl.gif

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Thank you Elrond,As you may have noticed, I was too impatient to wait for the PC400 you recommended previously, so I set myself up with the ASUS A7V333 MB and PC2700 DDR RAM. From your excellent explanation above (so many details in such an eloquent post), it appears that I too will realize improved performance if I increase my FSB speed. This I am interested in, and my BIOS will support the OC. However, I have no intention to do this until I have a better idea of what I would need to do, and what the potential dangers are (and the accompanying precautions). I will look forward to your links.BTW - I still need to set up one more "client" for WidevieW, so I think impatience will once again get the better of me. At least now (thanks to you and others on this great forum) I know how to build a system for relatively little cost.

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Hi Elrond,Thanks for the great info!I will be going with your recommendations (why does that word look so long? and why am I bothering to right this?) :-roll ...tions for the PC3000 as I now am running a Epox 8k3a DDR333 mainboard and as per your suggestions the PC3000 seems like a wise envestment. ;)Thanks Much!Paul

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