SATA DVD makes SATA HDD slower?

Jonesy1499

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Hi,

I read somewhere that having a SATA optical drive would make your SATA HDDs slower somehow, but I can’t find the page where I read it. I think they said the HDD would be slowed down to the speed of the DVD or something. Can someone clarify? Maybe I should get an IDE DVD?

Also, are there any disadvantages installation wise with getting a SATA DVD (like can Win XP recognice the drive when you install the OS, etc... )?

Thanks.
 

chookman

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Even the suggestion of this seems obsurd... The only way i can think of that the HDD would go at DVD speeds is if you were direct coping from DVD to the HDD, even then the only reason is because the DVD drive cannot read faster than the the HDD can write.

There are no disadvantages only advantages (which there arent many either) smaller cabling, better air flow, easier disconnect/reconnect.

Most new motherboards actually use the SATA ports for a fake IDE channel which make the drives work first time in installation. The main time this differs is when you want to run a system on a RAID config, then you usually need the drivers.
 

4745454b

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Perhaps you are confusing history with modern technology. Way back in the dark ages, IDE controllers used a transfer method called PIO. After that, they came out with DMA, and then Ultra DMA/UDMA. DMA started out at 16.6MBps, and finished at the 100/133MBps that we all know. The problem was when you hooked up an older PIO cd drive to a controller that had the faster DMA harddrive on it. IDE controllers can't run DMA devices with a PIO device on the same channel. This isn't a problem today because CD drives now also use DMA instead of PIO.

Confusion still exists today because of this. You can still find people on computer forums saying not to hook up a CD drive and harddrive on the same IDE channel because the CD drive will slow down the harddrive. This is wrong with modern IDE controllers however, as they have no problems running different speed DMA devices.

Remember that SATA is a serial point to point transfer, and you don't need to worry about this at all. There is no two devices on one channel problem like you have with IDE. You simply have device X on SATA0 or SATA2.
 

martyjs

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I've actually heard the reverse. my parts supplier was saying that if you don't use the IDE bus at all they have been seeing performance increases.

They supply some of our PC's as well, and do burn in performance test on every PC they build.
 

4745454b

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Sounds like BS to me. I can't even think of a possible reason as to how/why this would be the case. Can anyone else?
 

martyjs

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I trust these people. We have been buying off them for years and have no reason to tell me stories. The SATA and IDE Optical drives we buy are the same buy price and the same sell prices. :)

As I said in my previous post they do a lot of testing of there own, with both burn in's and testing to make sure products work together.
Their not a mass producing company but they do build lots of custom built units from base model system through to high end servers.

I can't remember the exact comment, I was ordering IDE optical driver's and they asked why as they were getting better results form an all SATA system.

Most of my customers are just computer noobs, not enthusiasts. :)

I'm not claiming their right and your wrong. Just that they haven't let me down in the past with false info. :)

 

martyjs

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I think they were referring to the total system through put. As the SATA bus is quicker then the IDE bus, if you aren't using the IDE bus there should be an improvement.

Anyone out there got some extra input. I haven't seen this mentioned anywhere else, but it sounds right. :eek:
 

4745454b

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Nope, its not through put either. IDE optical drives use the slower DMA 33 speed, you don't even need the 80 wire cable. You simply can't spin the optical drive fast enough to reach ATA100 speeds, and still have it be read.

As I said, I can't think of any reason why all SATA would be faster. I haven't seen anything one way or another, but it just sounds like BS to me. I'm not saying they are lying either, I just don't see how its possible. (thought they could be looking at something and misinterpreting the results.)
 

martyjs

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I don't know for sure either. I don't think they were talking about transfer rates for the drive, more to do with the bus speeds.
So if it does make a difference maybe Using the IDE Bus causes a bottle neck.
I'm only bringing it up again as I'm curious to know if it does make a difference.
This is the reason I'm a computer enthusiast. I'm not really interested in the fastest PC and such, but what are the possibilities.
New concepts, new ideas, keeps the mind ticking over.
 

cyberjock

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They might think they are telling you the truth when in fact they are wrong. Nobody knows everything. Heck, what i'm about to write below is my thoughts, and they could be wrong too! The important thing is to be smart enough to know when it really will matter and when it won't.


I can't imagine how sharing a SATA DVD and SATA HDD matters. SATA is serial connections. Point to point transfers, IE NOT parallel! SATA DVD should not run in 'parallel' with a SATA HDD so it shouldn't matter. If someone does show benchmarks proving that when they hook up their DVD it goes slower, then the bottleneck is something else. Maybe a crappy SATA chipset design. BUT, as consumers we should expect that reguardless of the device it should not effect the performance of the other devices. This was one of the reasons SATA was superior. Serial connections are independent of each other.

Yes, back in the day IDE was limited if you hooked up a DVD ROM and HDD on the same channel. But with SATA the very definition of 'channel' is obscured. SATA0 and SATA1 is a separate channel. They no longer put 2 devices on the same bus. Each is individial and it's own. Even calling it a 'bus' is technically invalid as far as I know because it's point to point, only 2 devices are connected(card and device).

Overall however, there's 3 possibilities:

1. Connecting DVD and HDD slows down the HDD.
2. Connecting DVD and HDD doesn't freakin' matter.
3. There's a few special cases that this happens(IE crappy SATA chipsets, compatibility problems, etc).

If it's #1 I'd think that ALOT, and I mean ALOT of people would have realized something is terribly wrong with their brand spankin new build and they are VERY unhappy that their hard drive is running at snail speed.

If it's #2 then who cares? If you are truely concerned that this is happening, hook them up separately. Most motherboards have 4 plugs, so use 2 for hard drives, and 1 for DVD-ROM leaving the 4th one empty.

If it's #3 then the reason this problem hasn't creeped up is probably because the 'performance nazis' don't buy the $5 SATA cards, they buy the $200 RAID controllers. These same people also benchmark their systems like crazy and the $5 card buyers just care that their hard drive works. In the end nobody really notices because of the distinction between the consumer that doesn't care about performance, and the people that want to see every ounce of it.

Overall, make your own judgment. I use the above quite often to determine the likelyhood of someone's post having validity in terms with how likely it is. I'm voting #2 - no damn difference.
 

martyjs

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cyberjock, I don't mind being quoted and don't take offence(as I believe non was ment) about the reference and comments, but taking that quote from that post only makes it look like I'm blindly believing what my supplier said.
In my next post I said the following
martyjs said:
I don't know for sure either. I don't think they were talking about transfer rates for the drive, more to do with the bus speeds.

I listen to lots of different ideas, test and so forth and in my mind at this stage on the SATA issue alone the jurys still out.
On the IDE issue I still think it's possible that an IDE Optical drive "would possible run slower than a SATA optical drive when it comes to data transfer.

If that's proved wrong so be it. :)
 

4745454b

Titan
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On the IDE issue I still think it's possible that an IDE Optical drive "would possible run slower than a SATA optical drive when it comes to data transfer.

As I said before, you can only spin the disk so fast and have it still be read. 52X CD speed is the same no matter what bus is being used. A 52X IDE optical drive transfers as fast as a 52X SATA drive. 52X = 52X, the bus doesn't matter.

Also as I already mentioned, ATA33 is fast enough to handle the fastest optical drives. SATA drives are only coming out because IDE is going the way of the 8track.

If anyone wants to run some tests, go do so. Again, I can't think of a single reason why an IDE drive would slow down a SATA port, or a SATA device would slow down another SATA device. They are point to point serial buses. There isn't anything else on the bus.
 

NewbieTechGodII

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I hate the Indians, but I hate the Yankees even more. Still, it was worth seeing LeBrown having to leave the stadium in disgrace after the Yanks were getting clobbered.

 

Zorg

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Sounds like BS. As 4745454b said, there is more than enough bandwidth to run a PATA CD/DVD at full speed without any bottleneck. For that matter there is enough bandwidth on the PATA interface to run my Raptor with no bottleneck, assuming it was PATA. You need to get the exact situation that they say is causing the slow down, I can't think of any that would.
 

martyjs

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Your missing the point,
1: I've already said more than once I personally am not sure and only bought it up again to get some constructive input.

2: I'm theorising that maybe something to do with the bus speeds and how they talk to each other.
We already know that in the past Memory speeds, different bus speeds and such do make a difference when it comes to the total speed of the system.
Bottle necks have been found, maybe (I said maybe) these points we have been discussing do make a difference.

Personally I don't care one way or the other, but I like these kinds of discussions, after all isn't that what the forums are about.

I'm not saying your wrong 4745454b I'm just the type of person who likes to be 100% sure when I say something is wrong or right. :)
 

Zorg

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This can't even be discussed intelligently, because we don't know the specifics of the advice you were given. This is all pie in the sky conjecture, get the specifics then we can either agree or disagree.
 

4745454b

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Its because I can't think of a single reason as to how/why that I think even with specifics, its still wrong. Whats been proposed is as crazy as saying adding a printer will make your USB ports run in USB1 mode instead of USB2. There isn't any reason for either of these cases to be true.

The only "answer" I can come out with is they ran a test or two and misunderstood the results. The test is simple. Unplug all IDE devices (you might want to even uninstall the drivers...) and try a copy folder test on your harddrive. Is it faster with the IDE devices attached? I can't think of any reason as to why it would, or else I'd do the test myself.
 

martyjs

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Fine I won't say any more. I must say I'm a bit disappointed with such a negative attitude. :(
It's not like I'm trying to push a load of lies on people, just passing on some info that was given to me by a normally reliable source. (That I have continued to point out that I'm not fully convinced about myself)
Just thought it was interesting. Sorry I spoke :pt1cable:
 

4745454b

Titan
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Negative attitude? I thought its been perfectly fine. No one has started any name calling, no one has thrown any personal attacks. I would like it if you could get the info from the company so that we might have an idea of what they are talking about.

Nothing personal, but I do my best to stomp out "I heard/read from reliable source that X happens." I would be more then happy to eat my words if this can be proven, but myself and others can't even think of a logical reason as to how/why it would. Ask them for data/proof. Give us a theory has to how/why it would work. Don't just stand there and say "but it came from a reliable source, so it might be true." As I said earlier, many "reliable" intelligent people thought you shouldn't hookup a harddrive and CD drive on the same cable. I do my best to "stomp out" errors whenever I get the chance.
 

Zorg

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I'll say it again, he doesn't even remember exactly what they said. It's all far too nebulous to even discuss. Get the specifics and then we can discuss it. Otherwise I have to say it is all BS, because I can't think of any scenario that would cause that effect either.