The State of PC1066 at GamePC

[Adul]

http://www.gamepc.com/labs/view_content.asp?id=stateofpc1066&page=1&cookie%5Ftest=1

"Today at GamePC, we've done a nice little write-up about PC-1066 RDRAM memory technology for the Intel Pentium 4 platform. How it's evolved, how it works, and where it's going. We've taken a look at how yields have improved on RDRAM chips over the years, and noted a few tips on how to avoid getting ripped off by remarked PC-1066 chips. Also looked at are some of the major issues still facing RDRAM technology and what's stopping it from mainstream acceptance."

 

[Athlon4all]

Good read, I still think 850e+PC1066/RIMM4200 is a betyter solution than DCDDR.

 

[christoph83]

Originally posted by: Athlon4all
Good read, I still think 850e+PC1066/RIMM4200 is a betyter solution than DCDDR.

And out of curiosity....why?

 

[RaynorWolfcastle]

Originally posted by: christoph83

Originally posted by: Athlon4all
Good read, I still think 850e+PC1066/RIMM4200 is a betyter solution than DCDDR.

And out of curiosity....why?

Perhaps because, as of today, it's the fastest solution out for the P4... and it will be at least until Granite Bay hits... . Now, does the performance boost justify the price premium? It probably does for for some.

 

[christoph83]

Originally posted by: icecool83

Originally posted by: christoph83

Originally posted by: Athlon4all
Good read, I still think 850e+PC1066/RIMM4200 is a betyter solution than DCDDR.

And out of curiosity....why?

Perhaps because, as of today, it's the fastest solution out for the P4... and it will be at least until Granite Bay hits... . Now, does the performance boost justify the price premium? It probably does for for some.

Well first of all we dont know the exact price. A granite bay board + PC2700 DDR will be just as exspensive as a current PC1066 RDRAM solution. Even if the board is 50 dollars more than an RDRAM mobo...256mb PC2700 DDR is 35 dollars cheaper than 256mb PC1066 RDRAM per stick. It is assumed it will provide the same performance ( so far) as PC1066 RDRAM. And is an easy upgrade for the majority of P4 DDR users out there. And buying PC2700 DDR will provide support for intels future boost to DCDDR333.

In my opinion. DCDDR will be a better solution. We shall see.

 

[Athlon4all]

2 Reasons. Cost and Performance. Only official benchmarks will tell, but I doubt that there will be more than a 5-7% delta between GB+DCDDR266, SiS 655+DCDDR333, and 850e+PC1066 on 533fsb Northwood's. Honestly, I think that many people are goingv to be very disappointed with the performance of Dual CHannel DDR in comparison to the latest generation of Single Channel DDR and 850e. The performance delta between the 2 will increase to significant amounts only when 667fsb and Prescott is launched with Springdale and DCDDR333 and then, unless PC1333 is avialable with an SiS supporting chipset, only DCDDR333 will be able to supply Prescott with enough bandy.

In terms of cost, the cost will be tight between the 2. 2 128MB sticks of PC2100 Crucial costs $45 per stick, so $90. 128MB sticks of Sammy PC1066 costs $75, so $150. Also, 256MB of Sammy RIMM4200 costs $121. Now, the chepaest 850e board (Non-32-bit) is an Intel D850EMD2, costing $134. Now IIRC, even this Intel board does have PC1066 multipliers, if not, then the next cheapest that I know for sure has PC1066 is $150 (Msi's 850E MAX). Now, taking the MSi 850E MAX board, that evens things out to within $10 difference between GB and 850e (assuming a GB board costing $200). So, its going to be close. DDR333 is simply not necessary on 533fsb so thats why I choose PC2100 memory.

Only time will tell. I will recommend DCDDR if it is not as expensive as 850e, but I won't hesistate to rec 850e if its cheaper (which it might be)

 

[oldfart]

A little tease from our motherboard editor

Originally posted by: Evan Lieb

Originally posted by: Mr. Crisis
Ack, but Evan we can't wait so long!

Could you at least give us a hint about the performance relative to the 850E with Rambus 1066?

Just a tiny hint...!

It's faster.

 

[RanDum72]

if not, then the next cheapest that I know for sure has PC1066 is $150 (Msi's 850E MAX).

IWILL has an 850E board that is cheaper, around $134 over at Mwave. LINK.
As for DC DDRAM, it offers exactly the same bandwidth when using two PC2100 compared to a PC1066 RDRAM setup. A stick of Crucial 256mb runs at $65-70 while PC1066 RDRAM is around $150 so DC DDRAM offers huge savings for the same or greater performance. My guess is that DC DDRAM has lower latency than RDRAM, thus the performance advantage. Thats why I'm holding off upgrading my PC800 RDRAM.

 

[Athlon4all]

Yea, GB will be faster but how much? My bet is that it still will not be much more than 5-7%, but that's just my opinion.

Actually Randum, 2 128MB sticks of PC2100 Crucial will cost $90 at Crucial ($45 each, I just checked last night). But, I bet that GB/Sis 655 boards will be at least $30 (prolly closer to $50-60) more expensive tyhan 850e boards with similar featureset/manufacturer.

I just am not convinced that DCDDR will be the most cost effective solution and like I said, my bet is that performance will not be as great as many people may be thinking it will be, but only time will tell (Can't wait to see Evan's GB and 655 reviews!)

 

[fkloster]

My guess is that DC DDRAM has lower latency than RDRAM, thus the performance advantage. Thats why I'm holding off upgrading my PC800 RDRAM.

This is what I want to know more about....imho, I believe the latency would be worse for DCDDR than rimms. In addition, imho, hyperthreading GB will NOT be 5-7% faster than a hyperthreading i850e setup with PC-1066.

 

[oldfart]

Another thing to consider is overclockability. Many P4s can be overclocked to 166 - 170+ MHz FSB. An RDRAM setup will need to drop to 3X at those speeds unless you have some incredible quality RDRAM. DC DDR is no problem at all way past those bus speeds.

 

[Ilmater]

Originally posted by: fkloster

My guess is that DC DDRAM has lower latency than RDRAM, thus the performance advantage. Thats why I'm holding off upgrading my PC800 RDRAM.

This is what I want to know more about....imho, I believe the latency would be worse for DCDDR than rimms. In addition, imho, hyperthreading GB will NOT be 5-7% faster than a hyperthreading i850e setup with PC-1066.

Considering that currently DDR has lower latency, and we know (from what Evan Lieb said) that a DCDDR setup is at least a little faster than RDRAM 1066, could you please give at least some smidgeon of logic or evidence to back up this claim. I mean c'mon; that statement is total conjecture. At least act like you're basing it off of some logical thought process. Opinions are fine, but even they need some foundation in fact.

 

[fkloster]

1) Current DDR platforms have absolutely, positively, beyond a shadow of any doubt, NO latency advantage in real world system performance over pre-fetching i850e / PC-1066 systems. Get over the rambus/latency fallacys Ilmater...they are non-existant!

2) If GB comes out with the exact same bandwidth and shows 5% performance increase over i850e, I will be shocked

3) The reason I see GB having increased latency is the extremely complicated timing schematics that would be involved in syncing two seperate channels of DDR memory without achieving interferance. In addition, what will the cost of these GB boards?

4) Good point old fart....overclocking would 'appear' to favor GB for that reason...

 

[Insane3D]

<--Remembers to bookmark this thread for after GB is out...

 

[fkloster]

lol, listen, I'm actually very excited for GB and (secretly) hope it is faster than i850e by like 10%....its just it seems too good to be true from all I have read about the complexity of DCDDR implementation....yes we will see soon enough

 

[Chadder007]

Is DCDDR a new type of DIMM or will it just use regular DDR DIMMS in pairs kind of like RIMM's?
Like maybe 2 sticks of 256 megs of DDR = only 256 megs of RAM total in a DCDDR setup?

 

[fkloster]

Originally posted by: Chadder007
Is DCDDR a new type of DIMM or will it just use regular DDR DIMMS in pairs kind of like RIMM's?
Like maybe 2 sticks of 256 megs of DDR = only 256 megs of RAM total in a DCDDR setup?

GB will use regular PC-2100 Dimms in pairs for a maximum peak bandwidth of 4.2 GB/s Identical to i850e w/PC-1066

 

[oldfart]

Here is an example of an overclocked comparision between 850E and Granite Bay.

P4 2.26 overclocked to 166 MHz FSB, 2.8 GHz.

Granite Bay
17 x 166 = 2.8 GHz
5.3 GHz mem BW with DC DDR @ 333 MHz

850E
17 x 166 = 2.8 GHz
5.3 GHz mem BW IF you can run 4X for PC 1330 (not likely)
4.0 GHz mem BW if you run 3X for PC1000 (more likely)

Which will be faster?

 

[fkloster]

Originally posted by: oldfart
Here is an example of an overclocked comparision between 850E and Granite Bay.

P4 2.26 overclocked to 166 MHz FSB, 2.8 GHz.

Granite Bay
17 x 166 = 2.8 GHz
5.3 GHz mem BW with DC DDR @ 333 MHz

850E
17 x 166 = 2.8 GHz
5.3 GHz mem BW IF you can run 4X for PC 1330 (not likely)
4.0 GHz mem BW if you run 3X for PC1000 (more likely)

Which will be faster?

lol Old fart, don't forget.... the pro's that OC i850's don't buy 'B' chips...they buy 'A' chips for cheeper price and better performance...rambus needs higher multipliers and lesser fsb's...

i850E
25 x 120 = 3.0 GHz
3.8 GHz mem

 

[oldfart]

[/quote]i850E
25 x 120 = 3.0 GHz
3.8 GHz mem[/quote]
Understood...but....

Granite Bay
25 x 120 = 3.0 GHz
3.8 GHz mem

Graite Bay can scale higher that the 4.2 GHz mem BW (way higher), but RDRAM is stuck @ ~ 4.2 GHz until there is much better mem available.

the pro's that OC i850's don't buy 'B' chips...they buy 'A' chips for cheeper price and better performance

Newegg prices:
2.26 $192
2.4B $191
2.4A $198
2.5A $262

What was that about 2.5A being cheaper?

If you want to go cheap:

1.8A @ 150 FSB = 2.7 GHz $140

Granite Bay
18 x 150 = 2.7 GHz
Mem BW = 4.8 GHz

850E
18 x 150 = 2.7 GHz
Mem BW = 4.8 GHz IF you can run PC1200 (maybe with VERY GOOD RAM @ 4X)
Mem BW = 3.6 GHz if you run 3X PC900

 

[fkloster]

I deleted that quick when I found out Intel's porkin' people on the 2.5's... You have valid points old fart, but I disagree with your comment about rimms being held to 4.2 ghz ....many freaks over @ 3dmark are running their PC 1066 @ 1333 speeds without event...many times its the quality of memory controller that is holding the rimms back. It will be interesting, but I think you and I can agree on one thing for sure.... AMD NEEDS TO PULL THEIR HEAD OUT OF THEIR @SS....

 

[oldfart]

Yup. Interesting talking about this stuff with you. These numbers are all best guesses. Once the boards come out in a few weeks, we will know for sure what is the real deal. AMD is getting further behind all the time. When the 3.06 HT P4's and DC DDR boards are out in a few weeks, they will be that much further behind. They had better step up the pace on the Hammer release.

 

[Athlon4all]

Honestly, I do not know about the issue of how good current PC1066 is ocing. I have heard some people hitting PC1333, which is a pretty big thing, cause PC1333 could keep up with DCDDR333 on 667fsb.

I will say, that I used to agree with Fkloster on the PC1066 latency, but not I am not certain. X-Bit's July 533fsb Chipset roundup shows different. 850e+PC1066 gets 360 cycles in Cachemem while 845G+DDR333 gets 282 cycles. Honestly, I would really like to know where Cachemem went in Anandtech's benchmark suite. They used to use it, but now they've stopped (as has Ace's Hardware). See, in late 2001, Ace's Hardware posted a PC1066 test that showed PC1066 on 533fsb having lower latency than PC133 on i845 (207 cycles, 128Byte for PC1066, 220 something for PC133).

I really would like to see some real latency tests done for the upcoming Granite Bay/SiS 655 reviews at Anandtech so they can get to the bottom of the issue of PC1066 latency. One thing is clear, the latyency of RDRAM is getting better as it gets faster, I'd love to see PC1333 benchmarks

 

[aka1nas]

Are the current P4s HT capable? I.E., If I buy a GB mobo and a slower CPU <3.06GHz, can I still enable HT?

 

[fkloster]

Originally posted by: aka1nas
Are the current P4s HT capable? I.E., If I buy a GB mobo and a slower CPU <3.06GHz, can I still enable HT?

No. It is disabled in slower cpus