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 All About Harddisk Thread V2, Discussion for Good Harddisk

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everling
post May 6 2010, 02:17 PM

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Raw bandwidth: 3.0 Gbps = 3.0 gigabit/s = 3000 megabit/s = 375 megabyte/s

Now the SATA spec uses 8b/10b encoding for transferring data from the drive to the CPU; 20% of the bandwidth is used for error checking and correction.

375 megabyte/s * 0.8 = 300 megabyte/s

That is for data bandwidth, including any remaining protocol overhead.

Read benchmarks with SSDs on SATA 3.0 Gbps tend to hit a limit of about 265 megabyte/s, so I'm guessing either the SSDs had some bottleneck or we can assume an overhead of about 11% caused by the protocol and other factors.



As for why advertise Gbps, I guess because it is a lot easier to guarantee raw bandwidth than actual performance.

This post has been edited by everling: May 6 2010, 02:25 PM
everling
post May 7 2010, 12:31 PM

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It's not that unbelievable. nod.gif

Your Caviar Blue is probably a 250 GB platter or two smaller capacity platters. In either case, the areal data density is lower, forcing the drive to read more area to get your data. The F3s uses two 500 GB platters, higher areal data density, so it has to travel less area to get your data.

The same is likely with your WD Green. The older one (WD10EADS) uses three 334 GB platters, but the newer one (WD10EARS) uses two 500 GB platters. The Samsung one uses three 500 GB platters, which will definitely outperform the older WD Green three 334 GB platters.

This post has been edited by everling: May 7 2010, 12:32 PM
everling
post May 10 2010, 01:35 AM

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SATA 6.0 Gbps isn't that useful anyway. Most HDDs are only just pushing the SATA 1.5 Gbps limit. The only time the 6.0 interface is useful to HDDs is during burst transfers, and they run out of cache buffer pretty quick. Assuming perfect situation, the 64 MB cache will run out in 0.1 second (faster for less optimal situation), and then you're back to the physical limit, which will be close to SATA 1.5 Gbps speeds.

This post has been edited by everling: May 10 2010, 01:36 AM
everling
post May 12 2010, 09:40 PM

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QUOTE(fuzagi @ May 11 2010, 08:02 AM)
any lag? i bought a new 640GB green 64mb and its slow. from starting up windows to opening folders, surfing. i was using an old seagate 250gb and it runs smoothly. is the green supposed to be that slow?
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64MB? Sounds like one of those Advanced Format drives and you're running Windows XP, XP sucks on these modern drives.

WD has a utility to mitigate the problem for XP. You can read about the details regarding this issue and the utility in this article.

Alternatively, upgrade to Windows 7 or an alternative OS that recognises 4K sectors.
everling
post May 15 2010, 01:02 AM

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The 16, 32 and 64 are cache sizes. To me, they're of secondary concern in performance, nice to have but not important.

The WD Caviar Green is geared for environmental friendliness and the WD Caviar Black is geared for performance. If you want the best in either category, you should still read the reviews as WD's aren't always the best.
everling
post May 18 2010, 08:42 PM

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Looks like quite a number of people are going to regret their current motherboard purchase. sweat.gif
everling
post May 29 2010, 07:14 PM

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QUOTE(midnightproject @ May 29 2010, 01:17 AM)
how much hdd speed effect the pc performance? hmm.gif
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There is a huge difference in performance between a HDD and an SSD. Just be aware that it won't help things that are not bottlenecked by the HDD. Some gamers were terribly disappointed.

QUOTE(Top-Gun @ May 29 2010, 02:06 PM)
I was planning on getting a new PC based on the AMD 890FX chipset with the newer SB850 SouthBridge.
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The 890 isn't a solid upgrade from the 785. I was disappointed.

QUOTE(Top-Gun @ May 29 2010, 02:06 PM)
Was actually planning to get a Velociraptor 150GB as my main OS drive in this next build of mine, but then accidentally stumbled upon Anandtech's lengthy yet informative SSD article.. and my heart ached for an SSD.

Question:
As I'm mainly looking for day-to-day performance, would I benefit more from an SSD or 2xWD Velociraptors 150GB in Raid-0 (daily backups) in the following areas?

1. Multitasking multiple programs in background
2. Launching of applications
3. General 'snappier' feeling of running programs, etc.
4. Boot-up times (not so important as I can wait, but would be great for restarting PC)
5. Durability and longevity of the OS drive (quite important)

So, if the general comment is that SSDs are better, what SSDs would you recommend? I was actually looking at the locally available Intel X25-M G2 80GB SSDs as they are better performers over the cheaper X25-V 40GBs.

Or are there any other SSDs recommended that would give me a similar edge in faster performance, better random read/writes as well as low random access times?
For example, Anandtech's reviews on the Indilinx MLC seems to thrash the Intel's ones in sequential write speeds but how much does that translate to real-world snappy tests, as I'm coming from a mechanical HDD spinning @ 7200rpm, not coming from another SSD.

Or you could sway me back to the Velociraptors.

Thanks for the input.
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2, 3: Comparison of Western Digital Raptor WD1500ADFD and Intel X25-M 160GB SSD when starting 51 programs simultaneously
4: Intel X-25M VS WD Velociraptor Boot
5: Intel has stated that their 80GB(?) drives will be able to handle 100 GB of writes everyday for three years. Also, SSDs are practically immune to damage induced by shocks; you won't losing data by accidentally dropping it or hitting the computer.

When it comes to SSDs, you really should avoid the lower capacity ones. Most SSDs have good access times, especially if they have TRIM support.

I'm not sure about current Indilinx SSDs, but they were obscenely overpriced compared to Intel ones the last time I checked a few months ago. As for an alternative consideration, I bought a Kingston V Series G2 128 GB from Cycom at RM 899 (part no: SNV425S2128). While inferior to the Intel ones on performance, it is still far better performing than HDDs and has a larger capacity at a similar price point. I wouldn't waste my money on Velociraptors, it's going to be either SSDs for performance or huge HDDs for cheap storage.

QUOTE(munak991 @ May 29 2010, 03:11 PM)
How long more will SSD will dominate HDD market?
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The next planned market shock will be in Q3 or Q4 of this year when Intel releases the next generation of flash memory, double the capacity for the same price.
everling
post May 29 2010, 11:15 PM

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It probably might, but it's already so far ahead of HDDs that any more performance improvement might not be noticeable as you start running into CPU bottlenecks, which is what I tend to experience now.

As for whether you should buy one now, one consideration is the price. Let's assume that the hypothetical Intel X25-M G3 160GB quickly settles into the Intel X25-M G2 80GB price bracket and ignore any future price changes between the items I have mentioned, then the cost/GB would be like:
CODE
Intel X25-M G2   80GB   RM 815       RM 10.187/GB
Kingston V G2   128GB   RM 899       RM  7.023/GB
Intel X25-M G3  160GB   RM 815       RM  5.094/GB

But that's not likely to happen any time soon after the launch, so I think that unless your budget is tight, any decent but large capacity SSD will be a decent purchase.

I'd buy one and would then hope that the G3 doesn't come out and hit the price I paid for in the next three or so months. blush.gif

This post has been edited by everling: May 29 2010, 11:18 PM
everling
post May 29 2010, 11:24 PM

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That's simply not going to happen in the next few years. For the foreseeable future, SSDs will simply be the better performers and HDDs will be better at storage. But Seagate's work at producing a hybrid will be something to watch with interest, especially when the hybrid has 16 or 32 GB of flash cache.
everling
post May 30 2010, 04:57 AM

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QUOTE(Cyclonechuah @ May 30 2010, 02:48 AM)
if you're talking about game loading time, yes(only if you raid 0 or SSD)
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Based on my experience, some games don't even see a benefit for loading times. They either never load that much from the hard disk or already had the data cached in memory. I think the most clearest winner for SSD are for work-related stuff and anything that deals with lots of small files, like photo albums. Pure gamers might prefer to put their money in their CPU and GPU.

Amendment: Some games can benefit from SSDs and some do not.

This post has been edited by everling: May 30 2010, 05:05 AM
everling
post Jun 4 2010, 12:36 PM

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You will need a motherboard capable of supporting USB 3.0 for that to happen, but I would still buy a USB 3.0 external hard disk because it is a great future proofing buy.
everling
post Jun 7 2010, 06:28 PM

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I've lost a hard disk to a bad PSU. It wasn't a hard decision to spend a little more on the PSU after that.
everling
post Jun 8 2010, 09:22 PM

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They said the performance loss of an unaligned WD10EARS, or any 4K sector HDD, with Windows XP will be about 11% on average. But maybe that is without considering file fragmentation.
everling
post Jun 8 2010, 09:52 PM

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Generally, ignore the buffer size and take a look at the benchmarks instead.

They're only temporary buffers that gets exhausted in less than a second. You get a much bigger and permanent performance boost with larger platter sizes.
everling
post Jun 10 2010, 12:23 AM

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Background processes causing interrupts? Try exiting every other program you can.

Added on June 10, 2010, 12:28 amThe reallocated sector count, while a bit troubling, is a normal part of the hard disk's 'self-healing' process. HDDs normally do not allocated every single sector to the user's space, but keep a small reserve of sectors that it can then use to replace sectors that has gone 'bad'. As long it doesn't change for days or weeks, it may mean that it 'healed' itself successfully.

I don't know if you can RMA on that alone.

Not sure about the other problem.

This post has been edited by everling: Jun 10 2010, 12:29 AM
everling
post Jun 11 2010, 02:28 AM

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QUOTE(Lacus @ Jun 11 2010, 02:07 AM)
Well i personally think in hardwares, lucks play an important role. Not just only hardisk, even motherboards, gpu these days don't really last as intended. My WD Black still in good condition after 1 year+ of usage.
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Part of the reason for more frequent hardware failures is because they're becoming much smaller, so they have less hit points to absorb damage with before they die. And at those small sizes, cosmic radiation can have a bigger effect. a few months ago, cosmic radiation was quantified to have a larger than expected effect on RAM, making ECC RAM more valuable in the server-space. Expect to see more frequent failures as the process node and tolerances shrinks.
everling
post Jun 11 2010, 05:32 PM

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QUOTE(ReaperOfSoul @ Jun 11 2010, 11:25 AM)
Hey,
Will 2 sataII harddisk's running at raid mode on a sataI raid controller get bottlenecked? Need some advice here. Thanks
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Depends on a number of factors. Like what models are the HDDs, what are you using them for, what specific applications?

SATA 1.5 Gbps (aka SATA I), has a maximum theoretical transfer rate of 150 MB/s. The older WD Caviar Black 1 TB has an average read/write of 85 MB/s. Newer HDDs can hit 110 MB/s while older ones might be lucky to hit 75 MB/s.

If you just want performance, save up for a decent SSD and make sure your motherboard supports SATA 3.0 Gbps (aka SATA II) or SATA 6.0 Gbps. A single good SSD can outperform more than four regular HDDs in RAID-0 configuration, or more than 60 HDDs in worst case scenarios.

This post has been edited by everling: Jun 11 2010, 05:33 PM
everling
post Jun 11 2010, 06:12 PM

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Intel is planning a 50% price drop in SSD prices in Q4. Actually, they're planning to double capacity for the same price.
everling
post Jun 11 2010, 06:32 PM

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They're a lot more expensive and harder to manufacture than HDDs. Know all those 65m, 45nm, 32nm CPUs? Intel is using 25nm for the upcoming SSDs.
everling
post Jun 12 2010, 12:39 AM

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(80GB + 20GB) / (20 hours * 3600 seconds) = 1.38 MB/s

Maybe it's USB 1.0? Other possibilities are very heavy file fragmentation and lots of tiny little files (they incur a huge performance cost).
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