What is the largest read/write speed across normal 7200RPM HDD possible today?

[vawrvawerawe]

Over Christmas I built a home network system (not my home PC that I made other threads about - this home network is something completely different and is not at my house). It works great, only, despite Gigabit transfer speed across the network, I discovered something - gigabit is actually not very fast, compared to transfer speed within a hard drive. Then I did the numbers - gigabit is only 128MB a second. But that's not the only limitation. I can't remember the specifics off the top of my head, but basically in the end the real-time throughput between the PC HDD and the NAS HDD with a gigabit connection ended up to not more than around 40MB/s.

So what is currently the fastest real-life possible throughput of transferring files across different 7200RPM HDD, and how do you achieve it? And what are the current limitations that keep you from being able to transfer data across different hard drives at the same speed as within the same hard drive?

 

[brandonwh64]

You are restricted by HDD speeds instead of gigabit LAN (Unless you did a horrible job setting up the LAN). The reason why commercial NAS storage server transfer fast over a gigabit network is due to the 15K RPM drives that reside in them.

 

[Mindweaver]

Then I did the numbers - gigabit is only 128MB a second.

I'd like to know what you did along with those numbers... a gigabit connection is 1000mbps (megabites per second). There is other varibles you need to look at as well like cable type. Cat 5 will only handle 100mbps and Cat 5e and 6 will handle 1000mbps. You also, have to consider length, because they are only rated for 328 feet. Anything past that, and speed will drop.

Now you may not get the full 1000mbps on your Gigabit connection, but you're going to be doing a lot better than your said 128mbps.

 

[EvolvA]

I'd like to know what you did along with those numbers... a gigabit connection is 1000mbps (megabytes per second). There is other varibles you need to look at as well like cable type. Cat 5 will only handle 100mbps and Cat 5e and 6 will handle 1000mbps. You also, have to consider length, because they are only rated for 328 feet. Anything past that, and speed will drop.

Now you may not get the full 1000mbps on your Gigabit connection, but you're going to be doing a lot better than your said 128mbps.

I might be wrong, but mbps means megabit per second, so what vawrvawerawe said was righ, a 1000mbps is actually a 128 megabyte per second connection.

 

[Mindweaver]

I might be wrong, but mbps means megabit per second, so what vawrvawerawe said was righ, a 1000mbps is actually a 128 megabyte per second connection.

Aww you know what your right.. Good catch! mbps is megabites and MBps or MB/s is Megabytes... I stand corrected.. Now that I stop, and think about it.. I have a 1gb db backup that I move across the network and it takes over 10 seconds to move. Aww, but that would be nice to have those speeds.. hehehe

 

[EiSFX]

I'm thinking maybe you could try and do a dual line connection (i'm not sure if it works the same way as back in the day with Dial up and 2 phone lines and two modems to get double the speed) with that you would need at least two network cards. but like i said i'm not sure if it works that way through LAN/broadband connections.

 

[CJCerny]

There is quite a bit of difference between the transfer speeds of different makes and models of NAS boxes. If the problem is that you are only getting 40MB/s between your PCs and your NAS box, then the NAS box is probably the bottleneck. If you read a bunch of NAS box reviews, you'll see that the transfer rates vary wildly.

 

[Mindweaver]

You can always go Fibre Channel... but then you're talking about some serious money. anything past 328 ft ideally you would use Fibre.

EDIT: I'd have to look, but I'm pretty sure Fibre is up to 40Gbps. Looking at some Transceiver and I'm seeing 4 and 8 Gbps

 

[de.das.dude]

100MB/s is pretty much it. if you want more you need another line and a bridged connection. messy messy.

but you are crrently being restricted by your hdd.

 

[Aquinus]

I'm thinking maybe you could try and do a dual line connection (i'm not sure if it works the same way as back in the day with Dial up and 2 phone lines and two modems to get double the speed) with that you would need at least two network cards. but like i said i'm not sure if it works that way through LAN/broadband connections.

Ethernet doesn't quite work like this. You need to do some routing magic to get this to work and it probably won't be what you're expecting.

Keep in mind ethernet speeds are before overhead.

1000Mbit per second / 8 bits/byte = 125MB/s

Throw some overhead on that, plus a server loaded with 7z and you get:

Here is some output from a Ruby script I wrote to test local network bandwidth between two points. (This is off a Macbook Air with a Thunderbolt Gigabit Ethernet adapter.)

$ ruby client.rb
"Speed: 113.798 MB/s"
"Speed: 99.566 MB/s"
"Speed: 99.439 MB/s"
"Speed: 112.030 MB/s"
"Speed: 111.745 MB/s"
"Speed: 115.653 MB/s"
"Speed: 123.198 MB/s"
"Speed: 113.701 MB/s"
"Speed: 117.322 MB/s"

As opposed to 5Ghz wireless on the same Mac (but with other Wi-Fi traffic locally,):

$ ruby client.rb
"Speed: 21.056 MB/s"
"Speed: 20.429 MB/s"
"Speed: 17.128 MB/s"
"Speed: 21.954 MB/s"
"Speed: 17.587 MB/s"

 

[tokyoduong]

The highest SEQUENTIAL read/write speed for the fastest 7.2k rpm drives can get today is actually pretty close to 200MB/s. You are more likely limited by your LAN than HDD. But for a bunch of small and random files, the HDD speed will be much slower than a gigabit LAN can handle.

You are probably getting 40MB/s for several reasons.
-the HDD is doing other things also
-Your network/router is serving multiple active devices
-you are sending small files that are not in sequential order on the HDD(random performance is poor on HDD)
-distance/signal strength
-your network card/router/switch does not perform the max potential

 

[RCoon]

1Gbit connection is 128Megabytes/s, which is the speed you're getting. HDD's at 7200RPM are capable of 150Megabytes/s on average, with some burst above and below. 15000RPM drives are capable of faster but good look with those.
Max you'll get to a HDD over the network is 128MB, provided nothing else is being written to the drive and the connection to the NAS is Sata III or whatever, and dependent upon filesize and quanitity, you may get less. Going fibre to a HDD in a home is just retarded and pointless for 20MB/s more.

There is no such thing as stupid questions. Just stupid people asking inquisitve questions.

 

[Mindweaver]

Going fibre to a HDD in a home is just retarded and pointless for 20MB/s more.

I never said it was a smart thing to do.. Just a faster solution to cat. But with that being said.. I would still love to have fibre in my house.. hehehe I couldn't justify the cost at this point, but I hope in the near future it will be more of the norm to do so.

 

[RCoon]

I never said it was a smart thing to do.. Just a faster solution to cat. But with that being said.. I would still love to have fibre in my house.. hehehe I couldn't justify the cost at this point, but I hope in the near future it will be more of the norm to do so.

Me too, i hope that the practicality of the cable will improve, as at the moment its expensive and breakable, and with absolutely no domestic network provider bringing us faster interwebs, it probably wont happen for a while, only businesses need the speed for file transfers and backup. There just isnt much market for it in homes.

 

[Aquinus]

I don't know about you, but if you use CAT-6 you're lining yourself up for 10Gbps when it starts to become mainstream. Might take a while though, otherwise you're paying out the nose for an adapter. You also would need all endpoints to use 10Gbps so it could get costly since Intel's 10Gbps adapter (which uses PCI-E x8 2.0,) costs over 500 USD.

Intel E10G41AT2 AT2 Server Adapter 10Gbps PCI Expr...

 

[Disparia]

I don't know about you, but if you use CAT-6 you're lining yourself up for 10Gbps when it starts to become mainstream. Might take a while though, otherwise you're paying out the nose for an adapter. You also would need all endpoints to use 10Gbps so it could get costly since Intel's 10Gbps adapter (which uses PCI-E x8 2.0,) costs over 500 USD.

Intel E10G41AT2 AT2 Server Adapter 10Gbps PCI Expr...

Music to my ears. I remember when it more like $5000 for an adapter

Also, the AT line is a few years old now. Their latest series, X540, is a bit cheaper at $350 (single port) and $550 (dual port).

Intel Ethernet Converged Network Adapter X540-T1 -...

Of course, by the time switch prices drop within reach I expect adapters in the area of $100.

 

[Mindweaver]

I don't know about you, but if you use CAT-6 you're lining yourself up for 10Gbps when it starts to become mainstream. Might take a while though, otherwise you're paying out the nose for an adapter. You also would need all endpoints to use 10Gbps so it could get costly since Intel's 10Gbps adapter (which uses PCI-E x8 2.0,) costs over 500 USD.

Intel E10G41AT2 AT2 Server Adapter 10Gbps PCI Expr...

I just bought 3x 1000ft boxes of cat 6 and I've already started changing over everything to cat6.

 

[caleb]

The NAS limitations are usually bottle necked on the interface HDD->Ethernet.
A cat 5 cable will do 1Gb/s speeds on short ranges, you can run benchmarks p2p with PC's and you will see its the NAS that blocks the speed.
As for HDD speed my WD Black reaches 150mb/s copy speed d2d on large files.

 

[ChristTheGreat]

Cat 5 won't do gigabit, Cat 5e will do on a maximum of 100m.

Like others said, the limitation will be:

Random write, or big/small file, network cable (if not gigabit), Switch (if not a gigabit), controller (alot of NAS doesn't make full HDD speed, from what I have seen)..

that is why I always make a small server (lwo cost) so I make sure I have full HDD speed + full network speed.

 

[Deleted member 3]

Cat 5 won't do gigabit, Cat 5e will do on a maximum of 100m.

Cat5 and cat5e are both rated at 100MHz and thus have the same bandwidth. Cat5e has less crosstalk though.

 

[tokyoduong]

Cat5 and cat5e are both rated at 100MHz and thus have the same bandwidth. Cat5e has less crosstalk though.

Cat5 vs Cat5e
Network support - CAT 5 cable will support 10BASE-T and 100BASE-T network standards, that is it supports networks running at 10 Mbps or 100 Mbps. CAT 5e is an enhanced version of Cat5 that adds specifications for crosstalk (see below). Cat5e cable is completely backwards compatible with Cat5, and can be used in any application in which you would normally use Cat5 cable. However, the added specifications of Cat5e enable it to support Gigabit Ethernet (1000BASE-T), or networks running at 1000 Mbps.
Crosstalk - Crosstalk is the "bleeding" of signals between one cable into another, due to a process called induction. This effect can result in slow network transfer speeds, and can even completely block the transfer of signals over the cable. Cat5e cable has been improved over Cat5 cable in this respect, and crosstalk has been greatly reduced.
Bandwidth - The bandwidth of a given conveyance media is essentially it's information carrying capacity. The greater the bandwidth of a system, the faster it is able to push data across a network. Cat5 is rated at 100Mhz while Cat5e is rated at 350Mhz. This coupled with other more stringent specifications makes Cat5e ideally suited for networks which plan to operate at Gigabit Ethernet speeds.
Bottom Line: If you plan on to implement Gigabit Ethernet, go with Cat5e. Also, the small increase in price of Cat5e over Cat5 is more than made up for by "future proofing" your network's cabling infrastructure.

 

[Aquinus]

Bottom Line: If you plan on to implement Gigabit Ethernet, go with Cat5e. Also, the small increase in price of Cat5e over Cat5 is more than made up for by "future proofing" your network's cabling infrastructure.

I can't completely agree with this. I would have agreed with you many years ago but in this day and age the cost of Cat-6 cable is pretty low (granted it does cost more than 5e,) but the longevity of Cat-6 will enable you to truly future-proof your cabling since Cat-6 is rated for 10Gbps at up to 100 meters iirc. Also alien crosstalk and external noise is less of a problem on Cat-6 UTP cable. Unless you're running a ton of cables (20+ per bundle,) or live near a large source of EMI like power lines you shouldn't need anything like STP cabling either.

Cat5 and cat5e are both rated at 100MHz and thus have the same bandwidth. Cat5e has less crosstalk though.

I was going to say you were wrong but tokyoduong got to it first.

 

[newtekie1]

If you are only getting 40MB/s there is something other than the Gigabit connection limiting you. The fastest write is in the 150MB/s range, that is a Barracuda 7200.14, and the read speeds are only about 1MB/s faster for those drives.

And gigabit can easily sustain 120MB/s, so if you are only getting 40MB/s I'd look somewhere else. My guess would be the NAS is underpowered and that is causing the slow transfer speeds.

 

[jihadjoe]

Storagereview's leaderboard says the fastest 7200rpm drive now is the Hitachi Deskstar 7K4000. It outpaces both the new WD Black 4TB, and the Seagate Barracuda 4TB.

http://www.storagereview.com/best_drives

Performance - Our current top choice for consumer performance hard drives is the Hitachi Deskstar 7K4000. The 7K4000 outpaces all other consumer 4TB hard drives and maintains price parity, making it the easy choice for those who want a high-speed, high-capacity hard drive.