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#1
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ST4000NM0035 vs ST4000NM0033
For at 4 TB drive sitting internally in a SuperMicro server as an
ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over ST4000NM0033? I can see that the newer one are having a slightly faster theoretically internal speed, but otherwise they look quite the same. Are the newer ones worth the price difference? Regards, Lars. |
#2
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ST4000NM0035 vs ST4000NM0033
Lars Bonnesen wrote:
For at 4 TB drive sitting internally in a SuperMicro server as an ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over ST4000NM0033? I can see that the newer one are having a slightly faster theoretically internal speed, but otherwise they look quite the same. Are the newer ones worth the price difference? Regards, Lars. ST4000NM0033 is 5 platter, 10 head. 175MB/sec OD ST4000NM0035 is 4 platter, 7 head. 205MB/sec OD --- higher areal density http://www.seagate.com/www-content/p...100671511f.pdf http://www.seagate.com/www-content/p...100793636c.pdf The '35 is 1 inch high. The '33 is 1 inch high. Both are 512n. The 7 head drive will have 8 heads, but one head will be ignored. Having two heads on each platter balances the forces on the spindle (to support all compass points as mounting options). StorageReview has pictures of the 33, but nothing on 35 that I could find. http://www.storagereview.com/seagate...n_e s3_review '33 has some failures. One here at 3 months. http://www.newegg.com/Product/Produc...82E16822178307 '35 has no reviews yet by customers. http://www.newegg.com/Product/Produc...1Z4-002P-00141 The newer one should actually be cheaper, if all that mattered was platter and head count. But you know there is more to it than that. Both drives mysteriously weigh the same amount. So the '35 has more metal in the chassis... or something. Paul |
#3
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ST4000NM0035 vs ST4000NM0033
Yeah - the density is higher, so the internal speed is therefor also higher.
1 platter less, lighter and cheaper, but maybe it has better bearings Actually I would imagine that one platter less should make it slower... Maybe I should stick to the older one? Regards, Lars. "Paul" wrote in message news Lars Bonnesen wrote: For at 4 TB drive sitting internally in a SuperMicro server as an ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over ST4000NM0033? I can see that the newer one are having a slightly faster theoretically internal speed, but otherwise they look quite the same. Are the newer ones worth the price difference? Regards, Lars. ST4000NM0033 is 5 platter, 10 head. 175MB/sec OD ST4000NM0035 is 4 platter, 7 head. 205MB/sec OD --- higher areal density http://www.seagate.com/www-content/p...100671511f.pdf http://www.seagate.com/www-content/p...100793636c.pdf The '35 is 1 inch high. The '33 is 1 inch high. Both are 512n. The 7 head drive will have 8 heads, but one head will be ignored. Having two heads on each platter balances the forces on the spindle (to support all compass points as mounting options). StorageReview has pictures of the 33, but nothing on 35 that I could find. http://www.storagereview.com/seagate...n_e s3_review '33 has some failures. One here at 3 months. http://www.newegg.com/Product/Produc...82E16822178307 '35 has no reviews yet by customers. http://www.newegg.com/Product/Produc...1Z4-002P-00141 The newer one should actually be cheaper, if all that mattered was platter and head count. But you know there is more to it than that. Both drives mysteriously weigh the same amount. So the '35 has more metal in the chassis... or something. Paul |
#4
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ST4000NM0035 vs ST4000NM0033
Reliabillity is supposed to be better on the newer one:
https://www.span.com/compare/ST4000N...33/58710-39360 Regards, Lars. |
#5
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ST4000NM0035 vs ST4000NM0033
Lars Bonnesen wrote:
Reliabillity is supposed to be better on the newer one: https://www.span.com/compare/ST4000N...33/58710-39360 Regards, Lars. Roughly the ratio of five platters to four platters, heads etc. And those are MTBF calculations, not actual field data. If Seagate gave us actual field data collected from previous models, I think you would be shocked at the correlation between MTBF and actual. Paul |
#6
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ST4000NM0035 vs ST4000NM0033
But with a better MTBF, I guess Seagate expect the newer ones to be more
reliable than the older ones. Regards, Lars. "Paul" wrote in message news Lars Bonnesen wrote: Reliabillity is supposed to be better on the newer one: https://www.span.com/compare/ST4000N...33/58710-39360 Regards, Lars. Roughly the ratio of five platters to four platters, heads etc. And those are MTBF calculations, not actual field data. If Seagate gave us actual field data collected from previous models, I think you would be shocked at the correlation between MTBF and actual. Paul |
#7
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ST4000NM0035 vs ST4000NM0033
Lars Bonnesen wrote:
But with a better MTBF, I guess Seagate expect the newer ones to be more reliable than the older ones. Regards, Lars. That's what the measure is intended to communicate. Normally, you would use the MTBF as a prediction of how many spares to stock in your stock room. I doubt the companies running large server farms rely on that manufacturer number, instead looking at how many failed Seagates or WDCs they had when using the previous model. MTBF is more of a ceremonial dance, than a useful metric. The manufacturer does have the information necessary to make the number realistic. However, if they did that, the marketing department would have the individuals killed :-) So instead, the calculation is done in "a standard way", devoid of the most recent field data. That's why I object to it. There is really nothing forcing them to be completely honest. As long as the numbers stay in a small range, nobody will suspect anything is wrong with the numbers. As an example, power supplies at work, the bigger ones are rated at 3000 FITs. And then a lab prototype of a smaller converter, had a rating of 100 FITS. And when someone calculates a value like that, you immediately start grilling them with questions. But if you showed me one unit is 3000, another 2500, then my suspicions are not aroused. Like you, I might expect (magically) that somehow the 2500 FIT one is better. (FIT equals failure in 10^9 hours). When there is an extreme change in these reliability numbers is when you become suspicious. To give another example of dishonesty, you will notice that some Helium drives have entered the market. And I was hoping that the environmental spec would take a radical shift. Instead, the specs are almost verbatim copied from existing drives. And you know when that happens, the marketing department said "don't scare the customers, don't arouse suspicions". The max altitude on a sealed Helium drive should be higher than the previous drives. Or at least, the number should be different, not exactly the same by chance. I'm patiently waiting for some failure rate data to come back from the Helium drives. By being sealed, they should not be subject to external moisture effects on the platters. Now, I wonder what the MTBF figures say... Would they reflect a difference ? Or not ? Paul |
#8
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ST4000NM0035 vs ST4000NM0033
On Sunday, 18 December 2016 18:02:41 UTC+5:30, Lars Bonnesen wrote:
For at 4 TB drive sitting internally in a SuperMicro server as an ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over ST4000NM0033? I can see that the newer one are having a slightly faster theoretically internal speed, but otherwise they look quite the same. Are the newer ones worth the price difference? Regards, Lars. Can we use both ST4000NM0033 and ST4000NM0035 in a RAID6, i.e for example can we use 2 nos. ST4000NM0033 and 2 nos ST4000NM0035 ?? |
#9
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ST4000NM0035 vs ST4000NM0033
wrote:
On Sunday, 18 December 2016 18:02:41 UTC+5:30, Lars Bonnesen wrote: For at 4 TB drive sitting internally in a SuperMicro server as an ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over ST4000NM0033? I can see that the newer one are having a slightly faster theoretically internal speed, but otherwise they look quite the same. Are the newer ones worth the price difference? Regards, Lars. Can we use both ST4000NM0033 and ST4000NM0035 in a RAID6, i.e for example can we use 2 nos. ST4000NM0033 and 2 nos ST4000NM0035 ?? For RAID, it's preferable to have drives with TLER (time limited error recovery). That helps prevent unnecessary array rebuilds due to the reallocation of sectors. TLER/CCTL https://en.wikipedia.org/wiki/Error_recovery_control Other than that, you could likely mix those two drives in RAID, as the slowest characteristic determines the overall performance. If one drive does 200MB/sec and the second drive does 210MB/sec, the 200MB/sec drive defines the response. If one has a seek time of 12ms and another drive has a seek time of 13ms, the 13ms drive determines the response of the array (for anything which cannot be hidden by that particular RAID array type). You also select drives rated for the vibration characteristic of the application. If the disks are going in a rack mount with a lot of other drives, an Enterprise drive might be better for that than a Consumer drive. An Enterprise drive with a piezo actuator at the head for fine positioning, is supposed to track better when the drive receives vibration from the drives next to it. Those are all considerations when selecting drives for RAID. Paul |
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