Rounded cable study?

[Mpegger]

I know rounded cables have been around for some time already. I've been thinking about rounding my cables too, but I've been held back by the fact that the 80 wires were laid out in that manner to prevent crosstalk (interferrence) between the data lines. With the cables tightly bundled together, I would think that some interference may occur, which would cause a loss in speed. From what I've read, the ATA controller chips will "throttle" a hard drive down to a lower speed if it detects too many errors of some kind in the signals. So if you had a ATA100 drive and there was too much interference, it would slow the drive down to ATA66 speeds to compensate for the noise. At least, that what I believe would be a side effect to rounded cables. But I haven't seen any testing done on such a theory. Or has there been? Anyone care to throw in thier 2cents or provide some urls to sites that have done testing? I'm really curious to find out if my concerns have some merit.

 

[KILLorBE]

I've seen a few tests, I've also seen one cable manufacturer that made them as shown in the pic (Red is ground, blue is signal or the other way around) they claimed it would perform upto 15% better compared to 'normal' rounded cables.

After reading that I did a test myself, took an ATA100 cable did a few benchmarks, cut it up, rounded it, and tested it again....no difference

I'll see if I can find the links.

 

[the_poche]

I rounded my cables too and I havent seen any differences. If there is one , well its not noticable to the naked eye.

 

[Mpegger]

Nice KILLorBe. I was thinking if I cut up my cables, I would cut them up the same way as you did in the pic. That way, the grounding cables would still be somewhat inbetween the signal cables.

Whats confusing me though is that if rounding cables doesn't affect performance, why even bother with 80 wire cable? The normal 40 wire sould work just as well if theres no crosstalk between cables.

Maybe something more then benchmarks would be needed. Isn't there some software that can test for hard drive reliabilty, like how many times it has to read a portion of a file to "get it right". I figure if (lets say) a file takes 5 passes of the head to read it entirely with a normal flat 80 wire cable, and 6 or 7 passes with a rounded cable, that would show that rounded cables do affect the signal quality. Maybe not the speed because of how fast todays drives are, but it could put added wear and tear on your drive if it has to make more passes just to read the information.

You wouldn't happen to know any sofware like that? I've only downloaded the regular hard drive benchmarks (speed), so I dont know what other kind of test there are available.

 

[Sonny]

I dont think you get added speed with rounded cables. The reason why people make it themselves is to save money compared buying them. Why use rounded cables? To clean up airflow inside the case by minimizing the area that a flat surface would constrict. If you think you can arrange them in a manner that would still be close to what the ground wires are there for then think again, after flexing the cables to fit the case they will be out of your desired cofiguration just like with flat cables. Yes just like flat cables, when you have another set of cables you get the "live wires" crossed with the ground wires. Try not to look too deep into this there isnt anything there that needs too much attention

 

[WyrmMaster]

The difference between a 40 wire cable and a rounded 80 wire cable is the 80 still has the ground wires in it, they may not be one between each data wire, but that is never the case ANY way. If you fold a flat cable it is going to put data wires next to data wires. But even with a rounded cable there are still 40 wires in that bundle, probably fairly well spaced out, that are ground wires.

 

[donny_paycheck]

I've compared flat, 80 wire cables to single device, rounded ATA133 cables and noticed that with my particular rounded cables I suffered an 8% performance loss in the ATTO benchmark. This was on a RAID 0 stripe of 2x 40g 7200 Maxtors.

 

[Xaotic]

I was wondering if anyone had seen braided cables for IDE interfaces? It would help with space and airflow considerations and might help with induced EMI. Most of the U160 SCSI cables I've used were braided to inhibit noise. Admittedly, since the wires are not at right angles on the crossings, there is a slight amount of crosstalk possible, but usually the wires are shielded internally as well. The 80 conductor IDE cables might benefit from braiding, especially if using a ground plane reference on external shielding surrounding the cables.

 

[Pcmod]

MMM, should I get rounded cables?
Are they worse speed?

 

[WinFlex]

Xaotic, can you explain how a braided cable would reduce noise in a SCSI application... i seem to not understand.
Also, does anyone have links to test sites that compared standart flat IDE cables with rounded ones...? If donny_paycheck is right, an 8% decrease in speed would certainly make me reconsider that set of rounded cables I was going to purchase!

 

[donny_paycheck]

I am going to write an article for the front page about my experiment very soon. I've been busy with school and stuff, but it will happen.

 

[Penguin4x4]

I have seen in an article the author folding the cables perpendicularerly(sp?), with the hard drive facing backwards. Then fold again, and again, and then attach the the outside of the unseen side of the hard drive cage, then attach to the motherboard connector. don't have the pic, but it looks there aren't any cables whatsover inside the case.

 

[Xaotic]

The trick with braided cables is that, any AC or digitally changing signal can induce voltages in nearby cables. The effect is strougest when the cables are parallel and no effect is possible when the cables cross at right(90 degree) angles. What braiding does is increase the angle of incidence between cables and thes reduce substantially the induced EMI(read noise in this case and another good example are the twisted pair wiring in network cable). The extra 40 conductors in an ATA 66-100 cables use a similar dodge by grounding the EMI to the planar(that's why it's polarity conscious). If the two techniques are combined, you'd probably have a relatively noise free cable. Shielding the cable and grounding the shield to the chassis would eliminate external noise by creating a shunt for exterior induction. I can probably find some links to explain further, but a trip to the library might be easier. The theories behind it are in the electrical section of physics books.

 

[Mpegger]

I have seen in an article the author folding the cables perpendicularerly(sp?), with the hard drive facing backwards. Then fold again, and again, and then attach the the outside of the unseen side of the hard drive cage, then attach to the motherboard connector. don't have the pic, but it looks there aren't any cables whatsover inside the case.

Thats what I've recently started doing to my flat cables. I've been folding them at 90 degree angles out of the way of air flow. I'll need to redo my main computers cables cause thier in no way, out of the way. I remember that one of those extreame PC sellers (forget thier names, but they always advertise in the gamer mags and sell systems with all the latest and greatest bells and whistles) actually hired a expert origami-ist to fold the cables in the case to get them out of the way of airflow. Then he taught the system assemblers how to do it. At least, thats what the company said.

 

[Mikey7]

New rounded cables

There is a review over at tweaktown on some new shielded rounded cables. couldn't creat a link so you'll have to search the title is Ioss rd3xp gladiator super shielded ata133 cables review. i'm generally not a fan of rounded cables but these look kind of interesting

 

[Mikey7]

New rounded cables

There is a review over at tweaktown on some new shielded rounded cables. couldn't creat a link so you'll have to search the title is Ioss rd3xp gladiator super shielded ata133 cables review. i'm generally not a fan of rounded cables but these look kind of interesting

 

[Exar Jun]

I have been making my own rounded cables for a while now. Any diff???? doesn't seem to be. But appearance and air flow have improved considerably.