5V or 3,3V PCI-connector on MOBO AOpen AX4C Max

[gere8888]

On page 51 of the manual ax4cmax-ol-e.pdf (ftp://ftp.aopen.ru/pub/manual/mb/ax4...4cmax-ol-e.pdf) is written:

As independent as Self-Powered PCI is, it comes in a seperate set of 3,3 volt power circuitry which supplies needed current and making it virtually free from the "loading issue" of traditional PCI slot.

The document "ink_12_02.pdf" (http://www.lavalink.com/fileadmin/ne...link_12_02.pdf) says the following:

PCI 2.1 and 2.2 both define six add-in card configurations, with support for 5, 3.3, and Universal (3.3/5 volt) signaling in both 32-bit and 64-bit bit variants.
Each card type is designed with notches, and each connector is designed with ridges, so that cards can "key" with compatible connectors only.

On page 19 of the manual ax4cmax-ol-e.pdf (ftp://ftp.aopen.ru/pub/manual/mb/ax4...4cmax-ol-e.pdf) you can see a picture of the motherboard.

The PCI-connectors on the motherboard AX4C Max have the ridge on the
right side (viewed when the motherboard is installed) which usually means that they are 5V-connectors.

What does it mean if in the manual is written that the Self-Powered PCI slot comes in a seperate set of 3,3 Volt power circuitry?

I believe that this is a mistake but the support of AOpen answered to my question:

Dear xxxx,

This slot is specially designed for PCI-cards like a SCSI or RAID cards, as they consume more power then conventional PCI-cards. If you have a older card that has 5V then this card is not supported on this mainboard due that it uses a Lower PCI-version then PCI 2.1.

Apologies for the inconvenience

Kind regards, Mit freundlichen Grüßen, Met vriendelijke groet,

AOE-FAE

This answer makes no sense because 5V PCI-connectors are supported up to PCI 2.3 and if the ridge of the PCI-connector is on the right side (viewed when the motherboard is installed) then it must be a 5V-connector.

http://www.lavalink.com/fileadmin/ne...ink_12_02.pdf:

PCI Revision 2.3 removes 5-volt-only cards from the specification, but retains the 5-volt only motherboard connector.

I need some clarification.

 

[phreakwars]

Basically what they are saying, is instead of the revision being made to support ONLY 5v cards as part of the specifications, They keep the same type of connector (right side) which was originally intended for only 5v use, but do not specify it as ONLY a 5v(the amount of current it outputs) slot. At least, this is what I am understanding from all of this.
.
.

 

[gere8888]

The 1st attached thumbnail shows Figure 4.1: 'PCI Board Connectors' from the document PCI Local Bus / Specification Revision 2.2 / December 18, 1998, page 114 (PCI-2.2).

It shows that there is one so called 5V-connector for the 5V signaling environment, and one so called 3,3V-connector for the 3,3V signaling environment.

And it shows that there are 3 expansion boards: one expansion board capabel of working with the 5 V signaling environment that fits only in the 5V-connector, one capbable of working with the 3,3 V signaling environment that fits in the 3,3V-connector and one universal expansion board capable of working in both signaling environments that can therefore be plugged in the 5V-connector or the 3,3V-connector.

PCI-2.2, page 113: The motherboard (including connectors) defines the signaling environment for the bus, whether it be 5V or 3,3V.

The 5V expansion board is designed to work only in a 5V signaling environment and, therefore, can only be plugged into the 5V connector. Similarly, the 3,3V expansion board is designed to work only in the 3,3V signaling environment.

However, the Universal expansion board is capable of detecting the signaling environment in use and adapting itself to that environment. It can, therefore, be plugged into either connector type.

All three board types define connections to both 5 V and 3,3V power supplies and may contain either 5V and/or 3,3V components.

The distinction between board types is the signaling protocol they use, not the power rails they connect to nor the component technology they contain.

PCI-2.2, page 137: All PCI connectors require four power rails: +5V, +3,3V, +12V and -12V. Systems that provide PCI connectors are required to provide all four rails in every system with the current budget specified in Table 4-10 (2nd attached thumbnail).

PCI-2.2, page 149: Table 4-14: Pin Summary - 32-bit Expansion Board (3rd attached thumbnail). It shows that the 5V Board (Board for the 5V signaling environment) is connected to the 5V and 3,3V rail and the 3,3 V Board (Board for the 3,3V signaling environment) is also connected to the 5V and 3,3V rail.

PCI-2.2, page 150: The maximum power allowed for any PCI board is 25 watts, and represents the total power drawn from all power rails provided at the connector (+5V, +3,3V, +VI/O, +12V, -12V, +3,3Vaux). The expansion board may optionally draw all this power from either the +5V or +3,3V rail.

On page 51 of the manual ax4cmax-ol-e.pdf (ftp://ftp.aopen.ru/pub/manual/mb/ax4...4cmax-ol-e.pdf) is written:

As independent as Self-Powered PCI is, it comes in a seperate set of 3,3 volt power circuitry which supplies needed current and making it virtually free from the "loading issue" of traditional PCI slot.

This explanation means to me that the Self-Powered PCI that comes in a seperate set of 3,3 volt power circuitry provides 3,3 volt power that is independent from the rest of the motherboard.

This should be no reason for a 5V-PCI-2.1-card not to work in a 5V-PCI-2.2-connector. The opposite should be the case: It should work better because of the independent 3,3V power supply. This would be at least what one would await.

 

[gere8888]

This is what the AOpen-Support repeatedly answered:

Dear xxxx,

This board does not support PCI-cards with 5.0 Volt as the 5Volt cards are to old! Therefore we do not support any request regarding these cards.

Kind regards, Mit freundlichen Grüßen, Met vriendelijke groet,

AOE-FAE

visit us at www.aopen.nl

Now I read something on http://www.pcisig.com/specifications/conventional/conventional_pci_23

Conventional PCI 2.3 - An Evolution of the Conventional PCI Local Bus Specification

Revision 2.3 is an evolutionary change to the PCI Local Bus Specification. Revision 2.3 makes a significant step in migrating the PCI bus from the original 5.0 volt signaling to a 3.3 volt signaling bus. Revision 2.3 supports the 5V and 3.3V keyed system board connectors (as did revision 2.2) but revision 2.3 supports only the 3.3V and Universal keyed add-in cards. The 5V keyed add-in card is not supported in revision 2.3.

PCI 66, PCI-X, Mini PCI, and Low Profile PCI support only 3.3 volt signaling on 3.3V keyed system board connectors and 3.3V and Universal keyed add-in cards.

High performance technologies power the logic within the chips with 3.3 or lower voltages. The newer high performance technologies cannot support 5 volt compatible signaling on the off-chip drivers. As a result, the host bridge needs to migrate to 3.3 volt signaling with 3.3V keyed system board connectors. Removing support for 5V keyed add-in cards is the first step in the migration to 3.3 volt signaling systems and ensures revision 2.3 compliant add-in cards will be usable in 3.3V keyed system board connectors.

In addition to the changes described above, revision 2.3 also incorporates other ECNs and approved errata. Compliance to Revision 2.3 will be required no later than January 1st, 2004.


PCI-2.3 supports:

3,3 V-Connector: Yes
5 V-Connector: Yes

3,3V-only-card: Yes
5 V-only-card: No
Universal-card (3,3V/5V): Yes

This leads to the problem that old 5V-only-cards plugged into a 5V-PCI-2.3-connector do not work.

This could be an explanation which would make sense.

But until now AOpen-Support did not answer the question to which specification (PCI 2.2, 2.3 or 3.0) the PCI-Slots are compliant to on the motherboard AOpen AX4C Max.