WILL THEY EVER MAKE AND AMD PLATFORM THAT SUPPORTS RAMBUS?

CtrlAltDel

Senior member
Aug 5, 2001
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Well thats the questio and i often wondered it........i know that amd would have to have a fsb to support it but then how would the benches look between amd and insmell?
 

Theslowone

Golden Member
Jul 30, 2000
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Intel and Rambus has a very big patent cross-licsense agreement that will probably prohibit any manufactuer from making an amd board with rambus.
 

gerrick

Senior member
Apr 10, 2000
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I often wonder this myself. Makes sense to me now that DDR and RDram are about the sam price. RDRAM has shown to have more headroom in it currently. Great thing about RDRAM is it's limited manufacturing. Only a few people make it so any RDRAm is good RDRAM. Not like that with SDRAM. I've never seen a bad stick of RDRAM before.
 

moocat

Platinum Member
Oct 25, 1999
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RDRAM is kind of out of it's element in a PC. It's got very high latency and is better suited to implementations that allow for mulitple pipes into main memory...such a super computer. The latency is much less of an issue when you are doing vector reads and writes and big block transfers to and from multiple processors armed with gobs of cache. I haven't looked at various benchmarks but I'm guessing that RDRAM performance is very "spikey" depending heavily on how the program is utilizing memory. A PC is too much of a multi purpose tool to take full advantage of the strengths of RDRAM.

Just my opinion, feel free to shoot holes in it...just be gentle :)



 

vss1980

Platinum Member
Feb 29, 2000
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howso? ddr is 266 while rdram is usually 800....so how is ddr better?

Quite easy actually. Currently official DDR DRAM speeds are 266 MHz (I'll ignore the fact its really 133MHz for those who still think DDR will deliver twice the throughput all the time), whereas official RDRAM speed is 800MHz.

Now, this is the fun part. DDR DRAM still uses a 64-bit memory bus width. RDRAM uses a 16-bit bus width and consequently on average will shift less information per clock cycle.
 

Theslowone

Golden Member
Jul 30, 2000
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Rdram properly implemented is better then ddr but properly implementing it is the problem. And if our systems had the need of the peak bandwidth that the rdram prides itself on.
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
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<< Intel and Rambus has a very big patent cross-licsense agreement that will probably prohibit any manufactuer from making an amd board with rambus. >>

AMD is a RAMBUS licencee. AMD already has the legal right to produce RDRAM supporting chipsets.

The problem is that with the current EV6 266MHz, the Athlon cannot take advantage of the additional bandwidth offered by RDRAM, in exactly the same way that the Pentium III shows no performance gains with RDRAM or DDR SDRAM.
 

Rand

Lifer
Oct 11, 1999
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<< Maybe when the Hammer is released will see motherboards the use RDRAM. >>



Then the chipset would have to bypass the integrated memory controller in the Hammer which would effectively neutralize many of the advntages of the Hammer.

AndyHui is following the right thinking though.
The 266MHz EV6 FSB of the Athlon can't take advantage of anything more then 2.1GB/s, so having anything more would be of no use to the processor which removes the bandwidth advantages of RDRAM, while it would still have to deal with RDRAM's higher latency.
Of course PC1033 RDRAM would have lower latency then current PC800 RIMM's which would push it down to nearly the latency od PC2100 DDR SDRAM, but then PC1033 is bound to cost more then PC2100 DDR, and the extra bandwidth it still wasted as the Athlon can't take any advantage of it.



<< Intel and Rambus has a very big patent cross-licsense agreement that will probably prohibit any manufactuer from making an amd board with rambus. >>



AMD has a license from Rambus to use RDRAM based technology in their chipsets and memory controllers if they so chose, SiS also has a license to use said technology on AMD platforms if they chose to.
 

Degenerate

Platinum Member
Dec 17, 2000
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<< I hope they won't. It's too expensive for me. >>

Well then you shouldnt consider DDR.



<< The problem is that with the current EV6 266MHz, the Athlon cannot take advantage of the additional bandwidth offered by RDRAM, in exactly the same way that the Pentium III shows no performance gains with RDRAM or DDR SDRAM. >>

So why did Nvidia introduce the NForce? i can see that the AMD CPU's cant take advantage of the massive bandwidth, so why bother? mabey its ready for a P4?
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
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nVidia's nForce has to share system bandwidth with the onboard graphics unit.
 

PUNKtotalled

Senior member
Jul 30, 2001
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"Well then you shouldnt consider DDR."

Here, DDR is two or three times cheaper than RDRAM. And in your country?
 

ST4RCUTTER

Platinum Member
Feb 13, 2001
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Then the chipset would have to bypass the integrated memory controller in the Hammer which would effectively neutralize many of the advntages of the Hammer.

It's my belief that AMD will go with both DDR and RDRAM (DDR for the Clawhammer and RDRAM for Sledgehammer). The high bandwidth of RDRAM is ideal for the hypertransport links provided in a dual or four-way processor server. As I have been shown, the MCT of the Hammer is generic and only the on-die DCT needs to be changed in order for RDRAM to be used.



Here, DDR is two or three times cheaper than RDRAM. And in your country?

Ahh...not anymore it's not...

 

Swanny

Diamond Member
Mar 29, 2001
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I still think DDR is a much better technology for the PC. Look at the bandwidth they provide. And the biggest issue, I think, is RDRAM's horribly high latency.
 

JeremiahTheGreat

Senior member
Oct 19, 2001
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RDRAM currently ONLY has higher bandwidth because its already in DUAL config.
PC800 RDRAM in DUAL config = 2 * 16bits * 800Mhz = 256000bits/s = 3.2GB/s..
PC2100 DDR in DUAL config = 2 * 64bits * 266Mhz = 34048bits/s = 4.2GB/s..
PC2700 DDR in DUAL config = 2 * 64bits * 333Mhz = 42624bits/s = 5.4GB/s..


Hmm.. who has higher bandwidth now? Dammit.. where's my 333FSB Thoroughbreds!
 

GoldMember

Banned
Jan 13, 2002
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still in the hole? .. haven't come out of your cave for a while?
Intel is quietly sweeping RAMBUS under the carpet.. why? It sucks compared to DDR.. Yes, it is fast.. also expensive way to expensive to justify the extra perfomence for most joe shmoes..

Also.. god.. I hate anything Intel.. YUCH! I just got the Intel microscope and it lacks a lot...
 

gerrick

Senior member
Apr 10, 2000
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Anyone who hates Intel or anything Intel does should have zero opinion in a question like this. The same is true for people who hate AMD and anything they do. RDRAM is very fast and stable. The memory manufacturing process is also very controlled. Only a few companies make it and all of it is good memory. That can not be said for SDRAM. The P4 can take advantage of RDRAM. It does very well. DDR on the P4 is not as good. It does win some benchmarks. Even SDR comes very close. The fact is RDRAM is a faster memory platform all the way around when paired with a P4. One of the biggest issues around is software. Not to many programs exist that can fill the memory bus.

I also like how everyone is throwing around theoretical numbers as far as bandwidth also. Those numbers mean nothing. RDRAM is able to keep up with anything DDR can do. The RDRAM roadmap looks very good also.

Intel is not sweeping RDRAM under the rug. They just released a chipset to regain some market share. That is called business. you may want to read up on it. RDram will get a large boast in a few months when the bus climbs to 533. Since RDRAM and DDR run neck and neck in price in the USA I don't see RDRAM going away anytime soon. The future of RDRAM is just as bright as that of DDR.


BTW isn't AGP an Intel thing?
 

Degenerate

Platinum Member
Dec 17, 2000
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there was another thread with a latency comparison, it basically says that as RDRAm gets higher in speed, its latency DECREASES, while DDR INCREASES when higher clocked. It was shown that PC1200 RDRAM was something like 30% lower latency that a DDR PC 2700. My figure ma be wrong.