pci cards

yeah...i knew i was using it in the 66mhz slot...but i just checked to make sure it was a 66mhz card and it is:

http://www.promise.com/marketing/datasheet/file/FTTX2000_v3.p df

Click to expand...

well, i just read that link and although it says that it is a 66mhz card that supports double data transfer rates...it is still in fact a 32 bit card...

ok, the cheapest i've found so far are here:

http://www.logicalplus.com/megmp649raid.html for $29


or here

http://www.ewiz.com/detail.php?p=LSI-R133_2&c=pw for $64

these are both keyed for the 64 bit slots, but are officially only 32bit/33mhz cards.

i couldn't find anything that was officially 66mhz and ata 133 RAID until i get into the $100 or so range - if someone does please let me know.

anyway, would either of those two cards be fine in a 64bit slot? or does anyone strongly recommend against them??

I think there is some confusion here, about PCI slots.

Your normal PCI slots are 33 MHz and 32 bit. The two 66 MHz slots on the K7D are 66 MHz, and 64 bit. Now, if your PCI card is normal length, but has two keys cut out, it is 66 MHz, or 66 MHz compatible. If it only has one key cut out, it is just 33 MHz.

If your card is extremely long (longer than a regular PCI card) then it is 64 bit. That extra length of those PCI slots is where you get 64 bit. (If you have a 66 MHz, 64 bit PCI card, it will have three cutouts.)

Not all 66 MHz cards are 64 bit, not all 64 bit cards are 66 MHz.

You can, very well, have 66 MHz, 32 bit PCI cards. You can also have 33 MHz, 64 PCI cards. My SCSI card is 33 MHz (but 66 MHz PCI slot compatible) and 64 bit. My old RAID card was 66 MHz and 32 bit.

Here's the bandwidth lowdown.

-The peak bandwidth of a "Normal" 33 MHz, 32 bit PCI slot is 133 MB/s.

-A 33 MHz, 64 bit PCI device has a peak bandwidth of 266 MB/s.

-A 66 MHz, 32 bit PCI device has a peak bandwidth of 266 MB/s.

-A 66 MHz, 64 bit PCI device has a peak bandwidth of 533 MB/s.

Now, the MPX chipset has this behavior with its 66 MHz, 64 bit PCI slots.

If you run two cards in both of the 66 MHz, 64 bit slots and one is a 66 MHz PCI card, but the other is a 33 MHz PCI card (66 MHz compatible), then the bus will slow down to 33 MHz. Generally, this isn't a big deal, but if you run a 33 MHz (but 66 MHz compatible) NIC or something, in one of those slots, it will limit the bandwidth of the other device, if the other device is a 66 MHz device.

Now, if you run two cards in both of the 66 MHz, 64 bit slots and one is a 64 bit, but the other is a 32 bit, then the bus doesn't slow down. The 64 bit device has its normal bandwidth, and the 32 bit device has its normal bandwidth.

One last thing

The 33 MHz PCI bus, for those "normal" PCI slots, below the 66 MHz, 64 bit slots, have a known issue.

This bus (totally separate from the other bus) has a latency issue, which messes up its peak bandwidth. These slots SHOULD be able to achieve 133 MB/s peak bandwidth, but they don't. This latency issue strangles the peak bandwidth down to about 40-60 MB/s. Now, for most devices (soundcards, NICS, TV cards, etc) this doesn't hurt anything, because they never come close to using the peak bandwidth, anyway. For disk controllers, however (SCSI, RAID, etc), this is a very bad issue. Hard disks actually reach 100 MB/s peak data transfer or higher. This latency issue really messes up their performance. RAID controllers reach up past 100-133 MB/s in sustained data tranfer rate. To choke the performance down to half of that, ruins the whole point of running RAID.

You don't want to EVER run ANY kind of disk controller in any of the 33 MHz PCI slots. Run them in the 66 MHz PCI slots, even if they are just 33 MHz (but 66 MHz compatible), otherwise your performance will be awful.

Very valuable post, cmcquistion. Thanks for it.

cmcquistion,
Related to the K7D master:

In an earlier post you stated "Don't worry about slowing down your southbridge to 33 MHz. It is a non-issue."

Could you elaborate on this? My guess is that the issue is whether you run the 66 slots at 66 or not. E.g. if you have a LSI U320, and a 15k scsi drive, you would be running at 66/64, maximizing the potential of the board, versus 33/32 or 33/64.

Are you saying that you do not need to worry about this unless you are running something like a 6 disk array where you may need the 566mb capability of the 66/64 configuration?

So, for my purposes, where I am trying to speed my system up (I currently have a IDE raid 0 with a Promise Fasttrak100 TX2 - a 66/32 card), I was thinking of adding a 15k scsi to use as a boot drive. Well, should I use a LSI u160 or u320. My understanding is that with the u160 (33/64) I slow the bus down, but with the u320 (66/64) I won't. The reason that I do not want to slow the bus down, is that I then limit my IDE drives to 133mb whereas with 66mhz, I gain 266mb via the Promise 66mhz card. I use this system for video capture and encoding, this the concern about speed and bandwitdth.

Thanks for your helpful post above.

Slowing down your 66 MHz bus to 33 MHz will limit your onboard IDE to 133 MB/s, but there aren't any IDE drives that transfer faster than that speed (the IDE controller, itself is only ATA 100, so it is limited to 100 MB/s, anyway). That is why I said it was a non-issue.

In your case, if you chose to use the LSI U160 card (33 MHz, 64 bit), then the card would be limited to 266 MB/s (which is lower than the theoretical 160 MB/s of the card's interface), so that won't be a problem. You will also slow down that bus to 33 MHz, but that won't adversely affect the devices that run off that bus (like the onboard IDE), because they don't need more than 133 MB/s of bandwidth.

Hope this answers your question.

May i have a question ?
Is my following assumption correct ?

If i put a 32bit and 33MHz and 64bit compatible, mass storage card into 64bit slot:

_ 64 bit slot: will slow down to 33MHz
_ 32 bit slot: 33MHz (ie: no change)
_ northbridge - southbridge interconnect: 33Mhz / 2 = 16.5MHz ?????????
_ southbridge frequency: 33MHz / 2 = 16.5 Mhz ?????

Thank you.

dualAthlon said:

May i have a question ?
Is my following assumption correct ?

If i put a 32bit and 33MHz and 64bit compatible, mass storage card into 64bit slot:

_ 64 bit slot: will slow down to 33MHz
_ 32 bit slot: 33MHz (ie: no change)
_ northbridge - southbridge interconnect: 33Mhz / 2 = 16.5MHz ?????????
_ southbridge frequency: 33MHz / 2 = 16.5 Mhz ?????

Thank you.

Click to expand...

You've almost got that right.

33 MHz ->will slow 66 MHz bus down to 33 MHz

32 bit -> won't slow down the bus or affect it in any way

North - Southbridge Interconnect -> I'm not sure what this runs, but I assume it is 66 MHz, and 64 bit, since it runs off the same bus as these 66 MHz, 64 bit PCI slots. In which case, if you slow down the bus with a 33 MHz card (that is 66 MHz compatible), then you will also slow down this connection to 33 MHz (if it is a 64 bit connection, it will stay 64 bit, but it might be a 32 bit connection, I'm not sure.)

cmcquistion said:

I have used the Highpoint RocketRAID 133 and RocketRAID404 in my K7D systems, with no problems.

*EDIT* The RocketRAID133 is a true, 64 bit PCI card. The RocketRAID 404 is 33 MHz, but it is 100% compatible with 66 MHz PCI slots.

Click to expand...

I have been looking and the Rocket raid 133 is 32 bit 33/66 compatable..
http://www.highpoint-tech.com/USA/rr133.htm

I could be wrong and thats why I am posting that link..

I thought the 64-bit slots connect directly to the Northbridge, and AMD just messed up the 32-bit slots (25 MB/s from what I hear).

You are an information warehouse ! I gave up on raid for this system.For now I wil stick to making the perfect case and setting up a killer water cooling system in advance of the techno upgrades in the future.

Beside with the cost of a strong Opteron dual system being what it is,waiting on hardware upgrades looks like the thing to do.....

cmcquistion said:

I have used the Highpoint RocketRAID 133 and RocketRAID404 in my K7D systems, with no problems.

*EDIT* The RocketRAID133 is a true, 66 MHz PCI card. The RocketRAID 404 is 33 MHz, but it is 100% compatible with 66 MHz PCI slots.

*EDIT 2* Corrected information above. The RocketRAID133 is 66 MHz, it is NOT 64 bit, as I accidentally posted.

Click to expand...

Does anyone know for sure where the Promise Fasttrak100 TX2 falls out in all of this? On the box, and on the spec sheet it says that it is a 66mhz card, but after reading all of the info above, I am thinking that may just be marketing speak for "66mhz compatable card".

My thoughts are that it is a 66mhz, 32-bit card.

I tried doing an ATTO 2.4 benchmark lastnight on my IDE raid 0 setup with the Promise card. I have two 120GB WB 7200 drives.
The raid card is in a 64 bit slot, and the other 64 bit slot is open. I seemed to get read speeds of about 70mb per second and write speeds about half of that.

Does this sound about right for my setup?

Thanks again for the useful info posted here.

I'm pretty sure the Promise Fasttrack100 TX2 is a true 66 MHz card.

Here is diagram for 762 northbridge

This post provides additional diagrams for what CMC said.

I found this from tech doc. Hope it provides useful info for everybody.

Its link here:
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/24416.pdf

Hey, we're using "CSA architect" like intel 875P here . GigaLAN and SCSI are connected directly to northbridge.

And pci 66 clock when 33MHz card is inserted

According to amd doc, when an (33Mhz, 64 bit compatible) is inserted into 66mhz slot, all PCI 66 buses (include interconnect bus between NB-762 and SB-768) will be SLOWED DOWN. So, i think we should always stick with 66MHz mass storage controllers.