Is there an upside to Rambus?

[tehtank]

I know the high bandwidth and low latency part of this, but what does that mean to me? Is rambus good at anything? Bad at specific programs or processes?

One thing that confuses me is how much people dislike it. Maybe it's my lack of experience talking, but I couldn't be happier with my rambus(although I do have a gig of it, might that be why?)

edit: my apologies, but it looks like I wasn't paying attention to where I posted this question, sorry

 

[Fluff]

People only dislike it because it. Costs more, and it had a higher latency.

If the market hadn't driven us to be using DDR. Maybe the P4 would have been much better using RAMBUS.

XDR looks much better than DDR2/3 on paper. And less traces etc.

Feature Summary
Memory physical description

1 to 32 bit native data bus widths
8 bank memory architecture
Point-to-point data interconnect
CSP packaging
Highest pin bandwidth


3.2 to 6.4 GHz data rate
Octal Data Rate (ODR) signaling
Bi-directional differential RSL (DRSL)
Programmable on-chip termination
Adaptive impedance matching
Highest sustained device bandwidth


6.4 to 12.8 GB/sec sustained data rate for x16 data bus width device
Up to 4 Bank-interleaved transactions at full bandwidth
Dynamic request scheduling
Early-read-after-write support for maximum efficiency
Zero overhead refresh
Low latency


1.25/2.0/2.5/3.33 ns request packets
Low power


1.8V Vdd
Programmable ultra-low-voltage DRSL 200mV swing
Low-power PLL/DLL design
Power-down self-refresh support
Dynamic data width support with dynamic clock gating
Per pin I/O power-down
Sub-page activation support
Ease in system design


Per bit FlexPhase circuits compensate to a 2.5ps resolution
XDR Interconnect uses minimum pin count

 

[Matthias99]

Originally posted by: Fluff
People only dislike it because it. Costs more, and it had a higher latency.

If the market hadn't driven us to be using DDR. Maybe the P4 would have been much better using RAMBUS.

XDR looks much better than DDR2/3 on paper. And less traces etc.

Well, also, RAMBUS (the company) generally are (or at least were) total bastards, and the reason their RAM costs so much is that it's a proprietary standard and they won't let anyone else make it without paying them a small fortune in licensing fees (if at all). Certainly it's very fast, but it just wasn't worth the higher cost and supply/licensing headaches, which is why it basically lost out to DDR once it most caught up in terms of speed.

 

[Peter]

Latency on Rambus RAM is extraordinarily high, it's been expensive and stayed that way, and it's quite difficult to handle in mainboard and DIMM design.

 

[TuxDave]

Is RAMBUS good for anything in regards to the consumer PC market? Nope... or at least not anytime soon. I talked to some engineers at Rambus to get their take on the company's position in the market. It seems that RAMBUS is more interested in products 2-3 years ahead and to be a viable solution in the PC market, you gotta be interested in products already developed and ready for mass production meaning it was introduced several years ago. So while Rambus may not be good for consumer PC memory, they still can make a heckuva high speed link.

 

[tehtank]

Matthias99, you say it's very fast, how is it fast? Does it load faster under specific conditions? Processors?

Peter, you say latency is high. What does that mean to me?(Someone who isn't the smartest with computers =p )

I'm very curious about this, because I don't understand why I get bitched out so much about my rambus =p

 

[cirthix]

haha, cause rambus is teh suck, thats y

 

[thermalpaste]

Originally posted by: TuxDave
Is RAMBUS good for anything in regards to the consumer PC market? Nope... or at least not anytime soon. I talked to some engineers at Rambus to get their take on the company's position in the market. It seems that RAMBUS is more interested in products 2-3 years ahead and to be a viable solution in the PC market, you gotta be interested in products already developed and ready for mass production meaning it was introduced several years ago. So while Rambus may not be good for consumer PC memory, they still can make a heckuva high speed link.

Intel's 820 chipset made people actually hate RD-RAM in those days (2000 to be precise). Wasn't Rambus's fault, Intel was to blame for the hub translator problems. Then when the pentium-4 was launched, we were compelled to buy prohibitively expensive RD-RAM.
Latency issues get sorted out once the CPU is fast enough. My PC-1066 RD-RAM would give me a bandwidth of 3040 Mbps on Sisoft sandra,which is faster than what my DDR-400 is giving me on my asus a7n8x mobo.

Rd-RAM heats up like a biatch though......

 

[tehtank]

So, rambus is actually good if used with a faster processor?

 

[thermalpaste]

RD-RAM is good, you do not need to worry about what people say about your RAM. This big plus point is RD-RAM comes with an ECC capability wheras a majority people using DDRs do not have this feature......

 

[Peter]

RDRAM doesn't "come" with an ECC feature, just as much as DDR does not not. It's all in whether you put the extra data bits onto your memory modules that the chipset requires for ECC-izing your data.

You're right in that non-ECC flavor of RDRAM DIMMs have never been defined. With SDR and DDR SDRAM, the market segmented into consumer DIMMs (no ECC, unbuffered direct connection of SDRAM chips to memory bus) and server grade (ECC, registers and clock PLL on DIMM).

 

[PsharkJF]

It would be interesting to see an Intel 3.6 paired up with 1600 RDRAM vs an AMD64 3600+ , since;
Intel architecture emphasizes bandwitdh over latenices, and AMD architectures are vice versa.

 

[thermalpaste]

Originally posted by: PsharkJF
It would be interesting to see an Intel 3.6 paired up with 1600 RDRAM vs an AMD64 3600+ , since;
Intel architecture emphasizes bandwitdh over latenices, and AMD architectures are vice versa.

Yes, absolutely true. Intel should have stuck to RD-RAM. I was using a PC-1066 RD-RAM and I could actually feel the super-fast bandwidth,I had an Asus P4T with a 1.5Ghz Pentium-4 overclocked to 2250 Mhz wheras the AMD Athlon 1800+ on a KT-333A mobo was kinda sluggish for me about 2 years back.

 

[Calin]

There is a place for RAMBUS in several types of memory interfaces (that require a small pin count). The memory speed per pin count is much better than for the DDR (and twice better compared to SDR). But the Pentium !!! was not advantaged by RAMBUS, and at some time RAMBUS costed like 1000$ for a 128MB module (something like 900$ I think). Even now, RDRAM is twice as expensive as DDR.
While RDRAM memory worked good on Pentium IV, a single channel RDRAM was similar with dual channel DDR, and the DDR solution was less expensive.
And I don't feel an actual Pentium IV is too disadvantaged by the limited bandwidth, as the performance doesn't improve so much when accelerating just the memory subsystem

Calin

 

[thermalpaste]

Originally posted by: Calin
There is a place for RAMBUS in several types of memory interfaces (that require a small pin count). The memory speed per pin count is much better than for the DDR (and twice better compared to SDR). But the Pentium !!! was not advantaged by RAMBUS, and at some time RAMBUS costed like 1000$ for a 128MB module (something like 900$ I think). Even now, RDRAM is twice as expensive as DDR.
While RDRAM memory worked good on Pentium IV, a single channel RDRAM was similar with dual channel DDR, and the DDR solution was less expensive.
And I don't feel an actual Pentium IV is too disadvantaged by the limited bandwidth, as the performance doesn't improve so much when accelerating just the memory subsystem

Calin

The pentium III was not good on an RD-RAM because the i820 chipset wasn't designed well and had hub translator problems. The pentium-4 is built to be 'lethargic'. The integer unit runs at twice the clock speed and the floating point unit is pathetic if we go to compare Unit CPU freq: performance ratio. The pentium-III had a big disadvantage ie: slow memory bottlenecking the CPU, which the pentium-4 doesn't have.....
RD-RAM is still good.

 

[Calin]

The hub translator problems appeared (if I remember correctly) only on the i820 chipsets that were modified to use SDRAM. The RDRAM i820 chipsets ran just fine.

Calin

 

[thermalpaste]

Originally posted by: Calin
The hub translator problems appeared (if I remember correctly) only on the i820 chipsets that were modified to use SDRAM. The RDRAM i820 chipsets ran just fine.

Calin

thanks for the info, I wasn't aware that intel had a mobo using only RD-RAM for a p-III because i never came across one......