BTX comments & Questions

[imported_Kaji]

The great mystery which is BTX has finally begun to unfold over the last month or so... finally!

This post serves for people to put any information they might know, and for those who would like to know more (like me!)

The designs are impressive... and give for excellent cooling of CPU and chipset. Not to mention a handy location for the Graphics card.

I have been reading that the BTX boards (the 1st ones anyway) will have ATX power connectors on them as well... for at least some small degree of backward compatibility (never mind the fact that you need a new case!). Does anybody have the faintest idea of what a BTX power connector looks like? Any pics or diagrams would be appreciated.

Another observation I have made is that the PCI-Express 16x slots on the BTX boards are about the size of an oldfashioned PCI slot... but the PCI-Express slots on current ATX server boards are much bigger (the size of 64-bit PCI slots) Does anybody have an explanation or any info regarding this?

All of the boards sizes showcased so far: BTX / MicroBTX / PicoBTX... all have only 1 PCI-Express 16x slot. Do you recon there will be boards with more? Will there be an Extended-BTX form factor???
I have not seen any mention of Dual CPU on BTX form factor. Anybody know anything about this?

I think this about covers my questions on the BTX form factor... for now at least.

The information I DO have came from THIS ARTICLE right here on anandtech.

Cheers!
Kaji.

 

[ant80]

Kaji
Junior Member

Posts: 1
Joined: 06/07/2004

Welcome to Anandtech.

 

[Yomicron]

Welcome to the forums :beer:

Originally posted by: Kaji
I have been reading that the BTX boards (the 1st ones anyway) will have ATX power connectors on them as well... for at least some small degree of backward compatibility (never mind the fact that you need a new case!). Does anybody have the faintest idea of what a BTX power connector looks like? Any pics or diagrams would be appreciated.

BTX power connectors are the same as for a modern ATX board, the regular 24 pin connector and one +12V 4 pin connector. The reason some have been saying that a new PSU will be required is because most BTX cases will be too small to fit an ATX supply. However full size cases will be able to accommodate a regular ATX supply.

Another observation I have made is that the PCI-Express 16x slots on the BTX boards are about the size of an oldfashioned PCI slot... but the PCI-Express slots on current ATX server boards are much bigger (the size of 64-bit PCI slots) Does anybody have an explanation or any info regarding this?

Current server boards do not have PCI-Express, they have PCI-X.

All of the boards sizes showcased so far: BTX / MicroBTX / PicoBTX... all have only 1 PCI-Express 16x slot. Do you recon there will be boards with more?

Most likely, but AFAIK there aren't currently any chipsets that support multiple 16x slots.

Will there be an Extended-BTX form factor???
I have not seen any mention of Dual CPU on BTX form factor. Anybody know anything about this?

I don't know.

 

[Wahsapa]

multiple pci-e 16x slots maybe, microbtx and picobtx with pci-e 16x, 4x and 1x yes... agp maybe even from via

i think chieftech or coolmaster or somebody makes a case that fits both atx and btx mobo's. i dont know exactly how it works tho.

 

[imported_Kaji]

Welcome to Anandtech.

Thanks!... guess I sortof skipped the formal introductions in my quest for more information.
Must Have Input!!! he he :laugh:

Got some good responses... Thanks Yomicron!

So those big slots on the server boards are PCI-X.... how does this differ drom PCI-Express?
Am a little confused now. I always though that those PCI-X slots were PCI-Express.

I'm assuming that PCI-Express is better / faster than PCI-X?

Those tiny little PCI-Express 1x slots are nifty, what are they likely to be used for? LAN? Audio?
I see PCI-Express 4x is mentioned.. is this also the same tiny little slot? what will the applications for this be?

Thanks for your input!

 

[pX]

PCI and PCI-X run on the motherboard's parallel bus (shared by all devices), whereas PCI-Express is serial and can operate all devices at full bandwidth... PCI, as you probably know, runs at 33 or 66Mhz. PCI-X runs at 66,100,133Mhz. PCI Express is at 2.5Ghz. Each PCI-Express "line" can handle 512mb/s (duplex). So 1x is 512Mb/s and 16x would be 8GB/s (duplex, so 4gb upstram and 4gb down), etc..

 

[pX]

Originally posted by: Kaji
Another observation I have made is that the PCI-Express 16x slots on the BTX boards are about the size of an oldfashioned PCI slot... but the PCI-Express slots on current ATX server boards are much bigger (the size of 64-bit PCI slots) Does anybody have an explanation or any info regarding this?

the PCI-Express 16x slots are a little bigger than normal PCI I think, think, I'm pretty sure it's for extra power.

Originally posted by: Kaji
All of the boards sizes showcased so far: BTX / MicroBTX / PicoBTX... all have only 1 PCI-Express 16x slot. Do you recon there will be boards with more? Will there be an Extended-BTX form factor???
I have not seen any mention of Dual CPU on BTX form factor. Anybody know anything about this?

From what I've seen, the only use for PCI-Express being discussed is graphics cards. So having more than one doesn't make sense. Someone correct me if I'm wrong.

 

[imported_Kaji]

From what I've seen, the only use for PCI-Express being discussed is graphics cards. So having more than one doesn't make sense. Someone correct me if I'm wrong.

There must be more use, as the reference BTX boards feature more than one PCI-Express slot.
Granted... only one of them is 16X and the rest are 1X or maybe 4X.

There is already a use for more than one 16X slot... Alienware has prototyped a Graphics solution based on Two Nvidia PCI-Express cards working in parallel with eachother (like the old Two Voodoo-2's only different)

I read it in THIS ARTICLE

 

[irwincur]

I still fail to see the major improvement to cooling that BTX offers. Not like it will matter, by next generation most cases will need to be watercooled anyways. Then it really does not matter where the CPU is located.

 

[Ryoga]

Originally posted by: Yomicron
BTX power connectors are the same as for a modern ATX board, the regular 24 pin connector and one +12V 4 pin connector. The reason some have been saying that a new PSU will be required is because most BTX cases will be too small to fit an ATX supply. However full size cases will be able to accommodate a regular ATX supply.

24-pin P1 connectors are found on WTX and the newer EPS power supplies intended for server motherboards. ATX P1 connectors have only 20 pins.

http://www.iwill.net/supports/power/?vID=170&SID=170&MID=26

BTX P1 connectors will be identical to those on ATX power supplies, but the form factor for the BTX PSU unit is not compatible with ATX (BTX is L-shaped, ATX is a cube). It's not likely that you'll find a BTX form factor case that will accommodate an ATX PSU.

Current server boards do not have PCI-Express, they have PCI-X.

Correct. PCI-X is a 64-bit parallel bus; it's an extention of PCI. PCI Express is serial. PCI cards will function in PCI-X slots (not sure about the other way around). PCI Express in incompatible with both.

Anandtech has a huge article on BTX basics:
http://www.anandtech.com/showdoc.html?i=1876

And an article about BTX boards shown at Computex 2004:
http://www.anandtech.com/showdoc.html?i=2070&p=3

 

[Ryoga]

Originally posted by: irwincur
I still fail to see the major improvement to cooling that BTX offers. Not like it will matter, by next generation most cases will need to be watercooled anyways. Then it really does not matter where the CPU is located.

You haven't seen the size of the thermal module, have you? Take a look here at the bottom pic. That stack of disk-like things that's as tall as the width of the case is the heat sink. Notice the amount of surface area. BTX enables the case to pull enough of an air volume across that heat sink to realize much better cooling.

And even if the CPU shifts to water cooling, the remaining components -- RAM, HDD, video, chipset -- will continue to be air-cooled.

 

[jackschmittusa]

I read recently that AMD will not be moving to BTX.

 

[Ryoga]

Not for awhile at least. The BTX form factor screws up AMD's on-die memory controller architecture. The trace lines have to go halfway across the board.

 

[AndyHui]

There are many uses for PCI-Express, not just graphics. Eventually, it will replace the entire PCI bus.

You can read more about PCI Express and what it does in this article:

PCI Express: Interconnect of the Future.