It appears you have not yet registered with our community. To register please click here...

 
Go Back [M] > Hardware Madness > General Madness - System Building Advice
PCI Express 16X slot voltage? PCI Express 16X slot voltage?
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read


PCI Express 16X slot voltage?
Closed Thread
 
Thread Tools
Old 31st May 2006, 22:29   #1
Liquid3D
 
Posts: n/a
Default PCIe 16X slot voltage?

Can anyone help me with this question please.

I need to know what voltages are avilable form the PCIe Slot. I understand this slot supplies 75W maximum, but at what voltage and amperes?

Second question: the 6-pin external connector, is this a stright 12V source or can the graphic card draw "up to" 12V?

For example the 12V4-Rails I know simply by mobo specifiation this external connector is limited to 18A (22A Peak for a 800W PSU) and tere's a formula for getting amperes from Wattage.

To get wattage the formula is simple:
P (Power or Watts) = volts x amperes

for amperes it seems to be watts / volts = amperes

SO what I'm getting at is, if the external power connector to a videocard is 12V and we know it's 16A then

12V x 16A = 192W ?

EDIT" JMKE the info King, found me som great info on this going to read it tonite. If anyone else is interested it'll be here.
 
Old 31st May 2006, 22:33   #2
Madshrimp
 
jmke's Avatar
 
Join Date: May 2002
Location: 7090/Belgium
Posts: 78,612
jmke has disabled reputation
Default

sorry for this reply not containing answers, but PCI-EX is extended PCI slots not PCI Epxress, the short name for PCI Express is PCIe

let's make reply more useful
http://www.interfacebus.com/Design_C...I_Express.html

PCI Express is the new serial bus addition to the PCI series of specifications. How ever the electrical and mechanical interface for PCI Express is not compatible with the PCI bus interface. This is a serial bus which uses two low-voltage differential LVDS pairs, at 2.5Gb/s in each direction [one transmit, and one receive pair]. A PCI Express link is comprised of these two unidirectional differential pairs each operating at 2.5Gbps to achieve a basic over all throughput of 5Gbps [before accounting for over-head]. PCI Express uses 8B/10B encoding [each 8 bit byte is translated into a 10 bit character in order to equalize the numbers of 1's and 0's sent, and the encoded signal contains an embedded clock]. PCI Express supports 1x [2.5Gbps], 2x, 4x, 8x, 12x, 16x, and 32x bus widths [transmit / receive pairs]; 2.5Gigabits/second per Lane per Direction. The 8B/10B changes the data transfer numbers to 250MBps per lane, raw data [B= Bytes, b=Bits]. The reduction in throughput is accounted for under the protocol section.
LVDS stands for: Low Voltage Differential Signaling.



The basic LVDS interface is a single differential link in either one or both directions. Each link requires a termination resistor at the far [receiver] end. The nominal resistor values used is 100 ohms, but would depend on the cable or PWB trace impedance used. LVDS is a scalable bus; one uni-directional link or multiple links may be used. The LVDS graphic above indicates a 1-meter length, but the PCIe specification only allows a 20 inch trace. Refer to the LVDS page for additional information
__________________
jmke is offline  
Old 31st May 2006, 22:55   #3
[M] Reviewer
 
Sidney's Avatar
 
Join Date: Mar 2004
Posts: 15,739
Sidney Freshly Registered
Default

Quote:
P (Power or Watts) = volts x amperes

for amperes it seems to be watts / volts = amperes

SO what I'm getting at is, if the external power connector to a videocard is 12V and we know it's 16A then

12V x 16A = 192W ?
it is correct from how/what I understand about electricity.

--------------

However, I'm not sure if 5 and 3.3V are required or not; if they do, they can be drawn from motherboard. The 12V 6-pin is to ensure sufficient direct power supplying to the video card rather than from the motherboard.
__________________
lazyman

Opteron 165 (2) @2.85 1.42 vcore AMD Stock HSF + Chill Vent II
Sidney is offline  
Old 1st June 2006, 13:41   #4
Liquid3D
 
Posts: n/a
Default

PCIe is what I mean. First it's important to clarify what we're discussing jmke has corrected me and I am grateful.

In fact I was writing PCIE16X which isn't necessary either because we all have to do is is be sure it's PCIe because the slot bandwidth ranges between 16 ~ 4X.
 
Closed Thread


Similar Threads
Thread Thread Starter Forum Replies Last Post
SPARKLE Presents GeForce 8400 GS PCI Express x1 Graphics Cards jmke WebNews 1 15th October 2008 16:26
Matrox Unveils World’s First PCI Express x1 Graphics Card: G550 jmke WebNews 0 19th July 2005 13:25
VIA Announces Support from Industry Leader for PCI Express Gigabit Ethernet Implement jmke WebNews 0 8th December 2004 13:50
VIA Announces K8T890, World’s First PCI Express Chipset for the AMD Athlon™ Processor jmke WebNews 0 25th September 2004 13:17
ATI Ships One Millionth PCI Express Graphics Card jmke WebNews 0 13th August 2004 13:05
NVIDIA Partners Now Selling PCI Express Motherboard and Graphics Combo Solutions Sidney WebNews 0 5th August 2004 07:45
NVIDIA Delivers Much Anticipated PCI Express Graphics Solutions Sidney WebNews 0 24th June 2004 23:07
ATI is graphics provider of choice for new OEM PCI Express systems jmke WebNews 0 22nd June 2004 16:28
IWILL Shows Dual Opteron, PCI Express Workstation Platforms jmke WebNews 0 26th May 2004 23:24
PCI Express & DDR2 - Good read jmke General Madness - System Building Advice 2 19th December 2003 21:29

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


All times are GMT +1. The time now is 18:15.


Powered by vBulletin® - Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO