Fiirewire 800 Vrs 400

[David WM]

I was wondering if anyone has some experience on the actual speed difference between DB's with FW 400 compared to DB's with FW800 for tethered shooting...ie is the FW speed a significant transfer speed limiting factor or is the transfer speed more dependent on other variables in the system?

Cheers,  David

[yaya]

I was wondering if anyone has some experience on the actual speed difference between DB's with FW 400 compared to DB's with FW800 for tethered shooting...ie is the FW speed a significant transfer speed limiting factor or is the transfer speed more dependent on other variables in the system?

Cheers,  David

Hello David,

On paper FW800 is supposed to be twice as fast as the 400 version for data transfer. In reality when using HDDs etc. it's about 30-60% faster.

With digital backs the speed depends also on the ability of the back to "cruch" the data and to push it down the cable and also on the computer end in terms of bus/ driver speed and the writing speed to the disk or to the RAM.

As a reference, if you look at the Aptus 75 (FW400) and the Aptus 75S (FW800 & faster processing), then you will see 1.6 sec/ frame for the former (with some buffer slowdowns) as opposed to 1.1 sec/ frame for the latter, with no slowdowns. Both backs use the same 33MP sensor and produce the same file size.

The same applies for using CF cards. Only the S can use the added speed of fast cards such as the Sandisk ExtremeIV range.

AFAIK the Leaf Aptus S, Aptus II and AFi II backs are the only ones that utilise the 1394b protocol/ driver to its maximum available speed.

This added speed also becomes useful when downloading images directly from the CF card through the digital back.

BTW on Windows based PCs, FW800 runs at 400 speeds due to lack of a suitable driver.

Hope this helps

Yair

[BJNY]

As a reference, if you look at the Aptus 75 (FW400) and the Aptus 75S (FW800 & faster processing), then you will see 1.6 sec/ frame for the former (with some buffer slowdowns) as opposed to 1.1 sec/ frame for the latter, with no slowdowns. Both backs use the same 33MP sensor and produce the same file size.

But, do they produce the same quality file?
Is there any cost of flushing the data off the back one half second faster?

[Snook]

But, do they produce the same quality file?
Is there any cost of flushing the data off the back one half second faster?

NO, There is not. Has nothing to do with compression...:+]
Snook

[BJNY]

I didn't think compression

just always curious
what's going on   under the hood.

[BJNY]

But, do they produce the same quality file?
Is there any cost of flushing the data off the back one half second faster?

This is why I asked:
Sinar's eVolution75H multi-shot tethers via Firewire800
yet can capture only 1 frame every 2.5 seconds
I recall being told this was to retain highest quality?

Mind you, the Aptus 75S has been my digital back of choice
since its availability, and because of its speed & quality.

[yaya]

This is why I asked:
Sinar's eVolution75H multi-shot tethers via Firewire800
yet can capture only 1 frame every 2.5 seconds
I recall being told this was to retain highest quality?

Mind you, the Aptus 75S has been my digital back of choice
since its availability, and because of its speed & quality.

You need to check if it uses FW800 bus/protocol/driver or just the hardware (port).

As a side note the increased speed of the A75S improves the quality of Live View as well.

Yair

[michaelnotar]

with my P25 i either use a 14ft FW 400 cable or a 30ft 6pin (FW 400) to 9 pin cable (FW800). since the back only supports 400, the 800 adds much more cable length while 400 is limited to just under 15ft, the 800 is powered.

[David WM]

Thanks Yair, I was wondering about the ability of DB's to use the speed. So it seems that Leaf is the only one to do this!

Any others?

David

. . .  On paper FW800 is supposed to be twice as fast as the 400 version for data transfer. In reality when using HDDs etc. it's about 30-60% faster.
With digital backs the speed depends also on the ability of the back to "cruch" the data and to push it down the cable and also on the computer end in terms of bus/ driver speed and the writing speed to the disk or to the RAM.
The same applies for using CF cards. Only the S can use the added speed of fast cards such as the Sandisk ExtremeIV range.
AFAIK the Leaf Aptus S, Aptus II and AFi II backs are the only ones that utilise the 1394b protocol/ driver to its maximum available speed. . . . Yair

[thsinar]

Not really!

Billy was speaking about the Sinarback eVolution 75 H, when speaking about the speed, not about the eMotion series: the previous is a multi-shot back, the latter is a single shot back. And there is a difference in speed between the 2 backs, when tethered: the eMotion 75 (equivalent to the one mentioned by Yair and which have to be compared) is less than 1.5 sec. per frame and depending on the computer used and uses a FW 400 bus.

So OF COURSE we do take advantage of the "FW800 bus/protocol/driver", to the contrary to what is suggested.

Best regards,
Thierry

Edited for Addendum

Thanks Yair, I was wondering about the ability of DB's to use the speed. So it seems that Leaf is the only one to do this!

Any others?

David

[BJNY]

What's also interesting is the 60 megapixel P65+ will capture at 1 second per frame
STILL using Firewire 400 cable.

Perhaps due to 1.3GB high speed ram?

[David Grover / Capture One]

Thanks Yair, I was wondering about the ability of DB's to use the speed. So it seems that Leaf is the only one to do this!

Any others?

David

Hi David,

Oh yes, there is always others.  ;-)

The H3D since the start uses FW800 and there is a small difference if you switch between 400-800 and a big advantage when you are copying UDMA enabled CF cards to the host computer.

Cheers,


David

[flashfredrikson]

Imho, and only imho, fw800 in dbs is plain marketing bs! I am sorry, but the there is no real speed advantage with fw800 yet, because readout speed is the bottleneck here (still). Thats why the new phase back with if i remeber right 4 readouts ist faster then most current 33/39 mp backs with two readouts, even though it has mor mp... it is faster then a p45+ or even a p30+.
What also comes into play is filesize. Hasselblad and sinar raws are bigger in MB due to a different compression than phase raws, which will take them longer to transfer tethered, maybe here fw 800 helps to get the same speed as phase with fw400.
But then you have to use fw 800 cables with those lousy plugs, which are also more expensive than fw400 cables... and who downloads photos from a card in the back? I would never even consider that, just use a fast cardreader...

just my 5cents

cheers

[BJNY]

Yeah, the fw800 plugs are a PITA
easily wiggling out of a MacBook Pro
unless the incoming cable is taped down

[thsinar]

It is a bit more complicated than what you stated here, and certainly not bs: would you imagine a manufacturer re-designing/re-writing the electronics, the casing, the protocols, etc ... only for the fun of being able to attach a FW 800 cable and claim that it is 800?

Beside this, a little correction: there is NO compression in Sinar RAW files by default, although there is the possibility to set a compression mode.

Best regards,
Thierry

Imho, and only imho, fw800 in dbs is plain marketing bs! I am sorry, but the there is no real speed advantage with fw800 yet, because readout speed is the bottleneck here (still). Thats why the new phase back with if i remeber right 4 readouts ist faster then most current 33/39 mp backs with two readouts, even though it has mor mp... it is faster then a p45+ or even a p30+.
What also comes into play is filesize. Hasselblad and sinar raws are bigger in MB due to a different compression than phase raws, which will take them longer to transfer tethered, maybe here fw 800 helps to get the same speed as phase with fw400.
But then you have to use fw 800 cables with those lousy plugs, which are also more expensive than fw400 cables... and who downloads photos from a card in the back? I would never even consider that, just use a fast cardreader...

just my 5cents

cheers

[David WM]

That is interesting.
Surely , with that amount of data to shift, if it would have an appreciable difference then Phase would have used FW800, or it may mean that the seed limiting factor is elcewhere in their system that makes the use of 800 meaningless, or maybe they are not that interested in tethered performance, in fact I couldn't see any mention of tethered speed on the data sheets. I suppose most users shoot to card.

It seems that there is more to tethered shooting speed than just the cable speed. Leaf seems to have a fast system designed for speed.  Sinar  eMotion 75 sounds like it achieves a good speed with FW400. It would be good to hear what all the back manufacturers quote for tethered operation, as it is the result that matters, not how they achieve it.

What's also interesting is the 60 megapixel P65+ will capture at 1 second per frame
STILL using Firewire 400 cable.

Perhaps due to 1.3GB high speed ram?

[flashfredrikson]

Did some quick research: FW400 is said to be capable of transfering 50 MB/s (just as a number), while FW800 in theory does 100MB/s
a raw (IIQ) file from a P45+ is 44MB, the P45+ shoots a frame every 1.5 seconds
from a h3dII 39 the raw (3fr) is 50 MB, shoots one every 1.4 seconds
P65+ the raw(IIQ) is 60MB, shoots  one pic every 1.0 second
(all this from the manufacturer's spec sheets, real world speed in my experience may and will differ ;-) )


where is the fw800 speed advantage of the hasselblad? isn't 3fr the format for cf-cards while fff is the tethered file format, which is bigger? I don't know...
will be interesting to see how well the P65+ really performs, waiting for it and it should arrive soon.

[Guy Mancuso]

Untethered it certainly does 1 FPS on the P65 Plus and i can feel it over the P25 plus at 1.5 does not sound like a lot but when shooting you will notice it. I did not shoot it tethered when testing but it should be exactly the same. Review time on my P25 Plus tethered is about 2 seconds in C1 and i would imagine the P65 is pretty much the same maybe a touch longer and both Firewire 400.