Wednesday, August 5th 2009

PCI-Express 3.0 Hits Backwards Compatibility Roadblock, Delayed

PCI-SIG (Special Interest Group), the organisation responsible for development of PCI specifications announced that generation 3 PCI-Express (PCI-E 3.0), is off its target launch time from late-2009 to Q2 2010. Although work on the bus is almost finished, there seems to be problems with implementing backwards-compatibility with older generations of PCI-E. Assuming PCI-E 3.0 is standardised in Q2 2010, one can expect implementing products (motherboards and expansion cards supporting PCI-E 3.0) only by a year later.

PCI-E 3.0 packs features that overcome the bottlenecks of PCI-E 2.0, such as the removal of the 8P/10b encoding scheme that added at least 20% data overhead for the 5 GT/s PCI-E 2.0, reducing it to 4 GT/s effective. At 8 GT/s the new bus will have effectively twice the bandwidth.Source: TechConnect Magazine
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62 Comments on PCI-Express 3.0 Hits Backwards Compatibility Roadblock, Delayed

#1
Mussels
Moderprator
by: Flyordie
False, sorta...
8x PCIe 2.0 is bottlenecking the HD3870X2's... So PCIe 1.1 x16 is surely at its peak usage with a GTX295.
those cards used a 1.1 bridge chip. invalid comparison.

by: hat
PCI-E 3.0 would be nice for SLI/Xfire on boards that don't do the full x16x/16x
Sure, when all the cards out there use 3.0.
Posted on Reply
#2
FordGT90Concept
"I go fast!1!11!1!"
Intel needs to focus a little less on PCI Express and a little more on USB.
Posted on Reply
#3
Mussels
Moderprator
by: FordGT90Concept
Intel needs to focus a little less on PCI Express and a little more on USB.
why, USB 3.0 is done and motherboards have already been announced with it.
Posted on Reply
#4
FordGT90Concept
"I go fast!1!11!1!"
Ah, available in 2010. Finally. I wish X58 had it though. :(

Actually, no, I don't care. I have zero USB devices. :laugh:

Oh, the irony. :wtf:


Nevermind me.
Posted on Reply
#5
NeSeNVi
"We don't need it yet, but we will need it soon"
Nathan Brookwood - principal analyst at Insight 64.

From what I heard PCIe 3.0 is expected to provide also lower power consumption than the previous PCIe 2.0 protocol.
Posted on Reply
#6
FordGT90Concept
"I go fast!1!11!1!"
by: NeSeNVi
From what I heard PCIe 3.0 is expected to provide also lower power consumption than the previous PCIe 2.0 protocol.
That's a bad thing. PCIE 1 & 2 support 75w of power through an x16 slot. Most cards have extra 12V power pins because they consume more than 75w. The wattage will most likely remain the same so older cards don't get overloaded (preserve backwards compatibility).
Posted on Reply
#7
Mussels
Moderprator
i beleive he meant it will consume less power on 3.0 devices, as in waste. Not that it will PROVIDE less.
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#8
FordGT90Concept
"I go fast!1!11!1!"
That's up to the device. :laugh:

Put a GTX 295 on PCIE 3.0 and it will still consume an elephants share of power. XD
Posted on Reply
#9
inferKNOX
by: CDdude55
But, im not saying we shouldn't go with the new slot at all. We really need to wait for the cards to truly utilize the slots. Having a new slot with more bandwidth and slightly new features every year or two isn't helping if we still have card finely chugging on an older slot.

Im not saying they aren't going to be useful in the future, but as of now there really isn't a big reason to go crazy about it.
The whole point is to precede the Graphics Processor manufacturers so that they have the freedom the explorer the possibilities and innovate further, not wait until there's a dead end, then act. They are being proactive rather than reactive, thus the rapid progression of technology. 3.0 is more for the GPU makers than you. Besides, it just makes it easier for people that are not on 2.0, they can just jump straight to 3.0 rather than going step by step and wasting resources.
by: FordGT90Concept
Intel needs to focus a little less on PCI Express and a little more on USB.
Huh? How is Intel involved here? It's the PCI-SIG (Special Interest Group) working on PCIe 3.0, not Intel isn't?

Sigh, the next mobo to move to will be one with PCIe 3.0, USB 3.0 & SATA-III.:respect:
LOL, you could say it's 3G, because it'll be PCIe 3.0, USB 3.0, SATA-III, DDR3 & for AMD users AM3 on HTT3!:roll:

EDIT:
by: FordGT90Concept
That's a bad thing. PCIE 1 & 2 support 75w of power through an x16 slot. Most cards have extra 12V power pins because they consume more than 75w. The wattage will most likely remain the same so older cards don't get overloaded (preserve backwards compatibility).
Don't forget there are also limitations on the mobos' bus, perhaps sending too much wattage through would overheat/overload the mobos.
Posted on Reply
#10
FordGT90Concept
"I go fast!1!11!1!"
by: inferKNOX
Huh? How is Intel involved here? It's the PCI-SIG (Special Interest Group) working on PCIe 3.0, not Intel isn't?
Intel was involved in its creation/standardization (still on the PCI-SIG board). It was also first introduced by Intel.


FYI, it is SATA 6 GB/s, not SATA III (SATA II is the group that set the specifications for SATA 3 GB/s). SAS already has some controllers that are 6 GB/s capable so it is pretty close to hitting mainstream, me thinks.
Posted on Reply
#11
Flyordie
by: FordGT90Concept
That's a bad thing. PCIE 1 & 2 support 75w of power through an x16 slot. Most cards have extra 12V power pins because they consume more than 75w. The wattage will most likely remain the same so older cards don't get overloaded (preserve backwards compatibility).
1.x= 75W
2.x= 150W
3.x= 200W (the cap, most will still cap at 150W.. its optional like Tessellation is with DX10)
Posted on Reply
#12
btarunr
Editor & Senior Moderator
by: Flyordie
1.x= 75W
2.x= 150W
3.x= 200W (the cap, most will still cap at 150W.. its optional like Tessellation is with DX10)
And those are not slot power. Slot power stays 75W.

6-pin connector = 75W, 8-pin connector = 150W, [unknown number]-pin = 300W (not 200W).
Posted on Reply
#13
Mussels
Moderprator
ding ding ding, BTA wins another cookie from mussels.


if the slots provided more power and cards used it, then you wouldnt be able to use the cards in an older slot design.

since you can use any 2.0 card in a 1.1 or 1.0 slot, its obvious they have not increase the power to the slot - because no cards use it.
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#14
hat
Enthusiast
Well why is there so much talk about pci-e 2.0 being 150w then?
Posted on Reply
#15
Mussels
Moderprator
by: hat
Well why is there so much talk about pci-e 2.0 being 150w then?
75 from the slot, 75 from the cable?


the standards probably include the cables.
Posted on Reply
#16
FordGT90Concept
"I go fast!1!11!1!"
Yup. Every pair is an additional 25w. 6-pin = 3 x 25w = 75w. The motherboard itself can provide up to 75w so 75w + 75w = 150w. Cards like the GTX 295 have a 6-pin and an 8-pin:

6-pin = 3 x 25w = 75w
8-pin = 4 x 25w = 100w
slot = 75w
total = 75w + 75w + 100w = 250w


I do believe these figures are important to power supply manufacturers. If they want to sell a PCIE 2.0-ready PSU, they need to make sure it has at least a 6-pin power connector (150w available to the card, total).
Posted on Reply
#17
ov2rey
by: FordGT90Concept
Intel needs to focus a little less on PCI Express and a little more on USB.
they should spend more time on improving Hard drive faster then SSD
Posted on Reply
#18
Mussels
Moderprator
by: ov2rey
they should spend more time on improving Hard drive faster then SSD
sure, they have made something faster than hard drives. SSD's.
Want something faster than an SSD? they have, they called them SSD's as well... lol.


why not ask for 2TB floppy drives while we're at it.
Posted on Reply
#19
ov2rey
by: Mussels
sure, they have made something faster than hard drives. SSD's.
Want something faster than an SSD? they have, they called them SSD's as well... lol.


why not ask for 2TB floppy drives while we're at it.
floppy drives too big.... cannot put inside pocket.. thumb drive is something that bring it to school and watch some nice media ^^
Posted on Reply
#20
FordGT90Concept
"I go fast!1!11!1!"
by: Mussels
why not ask for 2TB floppy drives while we're at it.
ZOMG! I want! :D

Floppy, floppy, floppy... :rockout:
Posted on Reply
#21
Hayder_Master
even new DX11 cards looks not used full pci-e 2.0
Posted on Reply
#22
MKmods
Case Mod Guru
by: a_ump
So when are they ever going to up the power provided to video cards through the slot? i kno that PCI-E 2.0 is spec'd to be able to provide 150watts, but for some reason that i can only assume about, they haven't implemented it with that yet.... That is honestly the only improvement i think PCI-E needs is to be able to provide it's specifications....not 75watts.
running more power through the poor mobo's traces is asking a bit much. The external power plugs will be the way to go.
150watts/12V = 12.5A... thats a lot to run through the mobo

( on a 6 pin cable the minifit molex connectors are rated for around 9A each but the wire if its a 16ga can handle between 13A(enclosed) and 22A(in free air) each. So if you go with the lower spec (minifit ends) a 6 pin cable for a GPU can supply about 27A (27A X 12V=324 watts. I havent played around with the 8pin plugs too much but I noticed they are the same as the 6 pin ones (3 yellows) they just add 2 extra grounds to them.
Posted on Reply
#23
madmanjohn
by: MKmods
running more power through the poor mobo's traces is asking a bit much. The external power plugs will be the way to go.
150watts/12V = 12.5A... thats a lot to run through the mobo

( on a 6 pin cable the minifit molex connectors are rated for around 9A each but the wire if its a 16ga can handle between 13A(enclosed) and 22A(in free air) each. So if you go with the lower spec (minifit ends) a 6 pin cable for a GPU can supply about 27A (27A X 12V=324 watts. I havent played around with the 8pin plugs too much but I noticed they are the same as the 6 pin ones (3 yellows) they just add 2 extra grounds to them.
Thats exactly where i was going to go as well- im going back into electronics history a bit here, but in the early days of the connector that evolved into the pci and pcie connectors of today, in the broadcast and audio recording fields were "edge card connectors".

Broadcast manufacturers like gates (harris allied) QRK and leagues of others all jumped on that technology in the late 60's early 70's and proceeded to guarantee employment for a lot of folks like me. They would build an entire console and transmitter parts as well based on this and if they needed more current just feed extra pins in paralell. new problem, too damn much heat, pins lose thier tensile strength, card pins start arcing, copper starts burning boards. and what once was the smell of success turns into a foul stench that means money in my pocket....

Next time you get to see the bottom of a mobo take a good look a how thin some of the traces are feeding that pci slot, and then there are feedthru points along the way that create more problems in a high current application.

When i got my first 780 chipset board i noticed in bios that you could assign a max wattage of 150w on the biostar bios for the pci slot and i just shuddered to think what would actually happen if a card tried to go there all on the slot power.

they have no choice, thats all an edge card connector will ever hold. but i bet we will see 8 pin molex with 4 b+ and 4 ground as the norm by 2012. just watch, its the only way unless they start making some real efficiant gpus with cooling that hasnt been thought of yet.

so its not so much because of backwards compatibility, but thats all those pins and copper can hold mathmatically and nothing can change that except for a radical new design in circuitbords and connectors, but not with things in existence as we know them today.

keep in mind 75 watts is considered average useage, and 150 is peak MAX , if your card tried to go to max for anything more than a few seconds hold time, it would not take long before you would see smoke-you can bank on that.
Posted on Reply
#24
hat
Enthusiast
by: Mussels
75 from the slot, 75 from the cable?


the standards probably include the cables.
but this is the same as pci-e 1.1, which is 75w... but there's the 75w from the cable as well so pci-e 1.1 is 150w as well :confused:
Posted on Reply
#25
Mussels
Moderprator
by: hat
but this is the same as pci-e 1.1, which is 75w... but there's the 75w from the cable as well so pci-e 1.1 is 150w as well :confused:
the standards can also include the option for more than one connector ;)


But thats what people are saying PCI-E 1.0 and 1.1 have the same power levels. both are 150W - the extra power only comes on cards that moved to 8-pin, or two plugs.
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