old pcie 1.0 card in a 3.0 slot and bandwidth

[Bill Dimwit]

Good grief another PCIe bandwidth question, but I can't seem to find any info out there on this question.

I have a older pci-e 1.0 4x raid card. I want to use in a more recent system, but it only has pcie 3.0 1x slot.
My question is will a pcie 1.0 card in a 3.0 slot be limited to pcie 1.0 1x speed or will it run a 3.0 1x speed? I'm thinking it might be a good idea to jut get a newer pcie 2 or 3 raid card. But it would be nice to be able to use the old card and not have to buy a new one to unleash 6 raptors in raid0.

Thanks for the help

 

[Johan45]

Should be backward compatible but won't work any faster than the cards design

 

[Bill Dimwit]

I'm not worried about backward compatibly. I know that will not be a problem. The raid card is a pcie 1.0 4x card and it will be put into a pcie 3.0 1x slot. I'm worried that it will be choked at pcie 1.0 1x speeds.

 

[Blaylock]

As you know the slots are backwards compatible therefore it will work at it's specified maximum speed.

 

[Bill Dimwit]

That's a little miss leading. The card is PCIe 1.0 4x and supports up to 1gbs. but will it be limited to PCIe 1.0 1x in a 3.0 1x slot? Or can it run at the full 1gbs in the 1x 3.0 slot?

The card is a HighPoint RocketRaid 2320
I'm guessing it would be limited to PCIe 1.0 1x

Thanks.

 

[Johan45]

Max speed will likely be whatever the on board controller can handel. It wasn't built for gen3, I don't understand the question here. I think it's pretty obvious.

 

[Blaylock]

PCIe 1.0 1x =250Mbs
PCIe 1.0 4x =1Gbs (250Mbs x4)
PCIe 3.0 4x =4Gbs (3.96Gbs Actually but who's counting since it's all theoretical at this point)

The Slot will not effect the cards speed in anyway. It will function at it's specified maximum speed.

 

[trents]

The data transfer rate would be limited by the theoretical bandwidth of the slot bus or the card, whichever is lowest. Notice I said "theoretical." Devices seldom live up to their theoretical bandwidth capacity in the real world. In fact, the real limitation may be the drives themselves rather than either the slot or the card. You never said what kind of drives you will be using in the RAID. Spinners? SATA/SSD?

Edit: Neither did you mention what kind of RAID setup you have in mind. Striped? Mirrored? My guess would be that if you were using SSDs in a striped RAID you might get some real world bottlenecking. Otherwise, not. That would be my guess.

 

[Bill Dimwit]

PCIe 1.0 1x =250Mbs
PCIe 1.0 4x =1Gbs (250Mbs x4)
PCIe 3.0 4x =4Gbs (3.96Gbs Actually but who's counting since it's all theoretical at this point)

The Slot will not effect the cards speed in anyway. It will function at it's specified maximum speed.

Ok so it will still be able to run at pcie1.0 x4 speeds on a 3.0 1x slot from what your saying?

- - - Updated - - -

The data transfer rate would be limited by the theoretical bandwidth of the slot bus or the card, whichever is lowest. Notice I said "theoretical." Devices seldom live up to their theoretical bandwidth capacity in the real world. In fact, the real limitation may be the drives themselves rather than either the slot or the card. You never said what kind of drives you will be using in the RAID. Spinners? SATA/SSD?

Edit: Neither did you mention what kind of RAID setup you have in mind. Striped? Mirrored? My guess would be that if you were using SSDs in a striped RAID you might get some real world bottlenecking. Otherwise, not. That would be my guess.

6 wd raptors in raid 0, maybe 8 down the road. Its in the op. Id say that more then enough to max out 250mbs.

 

[EarthDog]

Just one raptor will max out that card. Seems like the signals go all the way out to saturn and back on those older cards, eh? Time for a new one.

 

[trents]

6 raptors in RAID 0? I'd say that's living on the dangerous side.

 

[petteyg359]

A PCI-e 1.0 card is probably also SATA 1.0. For semi-recent drives, that's pretty worthless as a RAID controller.

 

[Bill Dimwit]

A PCI-e 1.0 card is probably also SATA 1.0. For semi-recent drives, that's pretty worthless as a RAID controller.

Its a sata 2.0 card and so are the hdds

- - - Updated - - -

6 raptors in RAID 0? I'd say that's living on the dangerous side.

How so? I been useing them in raid 0 for allmost 10 years. Never had a problem.

 

[petteyg359]

A PCI-e 1.0 card is probably also SATA 1.0. For semi-recent drives, that's pretty worthless as a RAID controller.

Its a sata 2.0 card and so are the hdds

SATA 2.0 is 8b/10b ECC, so 3 Gbps bus speed gives you 2.4 Gbps for actual data transfer. WD claims the SATA 2 Raptors can do 120 MBps (0.96 Gbps). Even in an x4 slot, which you say you don't have available, just two drives would be bottlenecked by the bus. Again, that controller could be useful for JBOD, or one of the integrity-focused RAID levels. It is (and was even when new) rather useless for gaining any speed.

 

[Lochekey]

I would say that if it is run in a 3.0 x1 slot you will be limited to running at 1.0 x1 since you will only be connected to the x1 connections on the board. Even though the slot is capable of handling 1 Gbs the card will only be able to handle 250 Mbs on the x1 connection of the board. The board will not be able to suddenly populate the full x4 bandwidth on just x1 of its connections. So the limiting factor in my opinion is the boards bandwidth across a pcie 1.0 x1 connection.

 

[EarthDog]

How so? I been useing them in raid 0 for allmost 10 years. Never had a problem.

a 10 year old any drive is more likely to fail than new. 6 drives acting as one... all it takes is one of those to go down...

... living in the edge indeed.

Why not sell those slugs and grab a m.2 pcie 3.0 x4 nvme drive which will be a lot faster.

 

[Bill Dimwit]

I would say that of it is run in a 3.0 x1 slot you will be limited to running at 1.0 x1 since you will only be connected to the 1x connections on the board. Even though the slot is capable of handling 1 Gbs the card will only be able to handle 250 Mbs on the 10C connection of the board. The board will not be able to suddenly populate the full 4x bandwidth on just 1x of its connections. So the limiting factor in my opinion is the boards bandwidth across a pcie 1.0 1x connection.

That was my thought. But I wasn't sure seeing the slot being able to support 1gbs and the card being able to support 1gbs if somehow it would be able to still run at 1gbs over pcie3.0 1x
I guess ill find out when I get all the parts for the system.

a 10 year old any drive is more likely to fail than new. 6 drives acting as one... all it takes is one of those to go down...

... living in the edge indeed.

Why not sell those slugs and grab a m.2 pcie 3.0 x4 nvme drive which will be a lot faster.

That doest bother me. I had older drives rinning in raid 0 for even longer. I have 11 20 year old scsi drives running in raid 0 in a older system. And yes the OS will be on a m.2 ssd. The raptors are for bulk storage. Good high end drives seldom fail out if nowhere and even if they do that's what backups are for.