Review Of 13 Sdhc Cards In Tom''s Hardware
- Thread starter cobaltage
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Heh, you beat me to the punch by about 20 minutes.
Tom's Hardware has many great reviews on just about any computer related stuff you could think of. Their frequently updated reviews for the best video cards for the money are invaluable.
P
Tom's Hardware has many great reviews on just about any computer related stuff you could think of. Their frequently updated reviews for the best video cards for the money are invaluable.
P
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hmm. i guess my recent experience with CF (compact flash) used as a hdd in a ppc osx desktop environment could be of remote interest here.
what i did was replace a g4 mac minis internal 2.5" hdd (PATA) for a high-end CF, with the two-fold idea to (a) further improve the desktops excellent heat signature, and (b) get rid of the original internal hdd which was just sitting there unused. that particular hdd model is notorious for its overly-aggressive head parking policy (giving an entirely new meaing to hdd latency) so its system functions had been promptly overtaken by a snappy external fw400 (iomega) drive. basically the system was running off that external drive at this stage.
for the purspose i picked a high end CF by transcend - namely their Ultimate 266X model (8GB) - an SLC-based, UDMA4-sporting, 40MB/s -rated piece of flash. not a cheap one, either.
after a careful surgical intervention (which in iteslf is somewhat of an exploit on a mac mini, but that is beyond the topic of this thred), i had the CF hooked to the miniIDE (44pin) connector of the internal PATA bus. results:
* compared to running off the external fw400 drive, the system felt notably less responsive - there were clear moments when processes were waiting for disk io, and also moments when the vmem system did the same. i should point out here that the fs of the system is a journaled one (jHFS+) - ie. there are supplementary disk writes to each genuine writing operation. bulk file transfers, OTOH, were quite snappy, particularly UDMA4 <-> fw400 transfers were both quick and not cpu-taxing.
* when i moved the vmem swapfile onto the fw400 drive, the situation improved notably - basically, it reached the original solo-fw400-drive responsiveness levels, with the difference that the entire fs (sans swap) now resided on the CF.
conclusions:
* while very capable in bulk transfer speeds, a high-end flash card is still no match for a command-FIFO-capable disk drive. particularly in situations where many small, unrelated reads/writes are present, the disk drive clearly outperforms a UDMA flash card, and that could be easilly felt. note that the bus factor is practically negligible in this test - both the external hdd and the internal CF "drive" are both sitting on DMA-capable, fast, low-latency buses. ok, fast compared to usb2 anyway.
* one way to alleviate that flash-card disadvantage is to interleave the tiny accesses to the fs across drives - put common offenders like a vmem swapfile onto a different drive, or generally stripe-RAID your fs, etc. also, be mindful of the type of fs you use with your flashes - journaled fs-es are particularly taxing on devices lacking deep command FIFOs.
well, that is it for today, hope that would be of use to somebody : )
what i did was replace a g4 mac minis internal 2.5" hdd (PATA) for a high-end CF, with the two-fold idea to (a) further improve the desktops excellent heat signature, and (b) get rid of the original internal hdd which was just sitting there unused. that particular hdd model is notorious for its overly-aggressive head parking policy (giving an entirely new meaing to hdd latency) so its system functions had been promptly overtaken by a snappy external fw400 (iomega) drive. basically the system was running off that external drive at this stage.
for the purspose i picked a high end CF by transcend - namely their Ultimate 266X model (8GB) - an SLC-based, UDMA4-sporting, 40MB/s -rated piece of flash. not a cheap one, either.
after a careful surgical intervention (which in iteslf is somewhat of an exploit on a mac mini, but that is beyond the topic of this thred), i had the CF hooked to the miniIDE (44pin) connector of the internal PATA bus. results:
* compared to running off the external fw400 drive, the system felt notably less responsive - there were clear moments when processes were waiting for disk io, and also moments when the vmem system did the same. i should point out here that the fs of the system is a journaled one (jHFS+) - ie. there are supplementary disk writes to each genuine writing operation. bulk file transfers, OTOH, were quite snappy, particularly UDMA4 <-> fw400 transfers were both quick and not cpu-taxing.
* when i moved the vmem swapfile onto the fw400 drive, the situation improved notably - basically, it reached the original solo-fw400-drive responsiveness levels, with the difference that the entire fs (sans swap) now resided on the CF.
conclusions:
* while very capable in bulk transfer speeds, a high-end flash card is still no match for a command-FIFO-capable disk drive. particularly in situations where many small, unrelated reads/writes are present, the disk drive clearly outperforms a UDMA flash card, and that could be easilly felt. note that the bus factor is practically negligible in this test - both the external hdd and the internal CF "drive" are both sitting on DMA-capable, fast, low-latency buses. ok, fast compared to usb2 anyway.
* one way to alleviate that flash-card disadvantage is to interleave the tiny accesses to the fs across drives - put common offenders like a vmem swapfile onto a different drive, or generally stripe-RAID your fs, etc. also, be mindful of the type of fs you use with your flashes - journaled fs-es are particularly taxing on devices lacking deep command FIFOs.
well, that is it for today, hope that would be of use to somebody : )
Your experimental results are quite in line with just about everything you read concerning flash storage... never, ever put swap on it 
Of course, in my case since the SDHC cards I buy will be used probably better than 95% for read, and that largely contiguous low-rate (moves, etc) I'll be quite well served by buying "cheap" class4/class6 cards.
P
Of course, in my case since the SDHC cards I buy will be used probably better than 95% for read, and that largely contiguous low-rate (moves, etc) I'll be quite well served by buying "cheap" class4/class6 cards.
P
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Yamara
Member
'Drenyx' said:
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Racemaniac
Scorched GP programmer
lol, i found an error in one of the graphs ^^
the one with minimum/average/maximum read speed ^^
for the first card, min is 19.4, average is 19.7, max is 19.6 ^^
the average is higher than the maximum, very interesting
the one with minimum/average/maximum read speed ^^
for the first card, min is 19.4, average is 19.7, max is 19.6 ^^
the average is higher than the maximum, very interesting
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Creature XL
Active Member
didn't read it to the end now, but this raises my interest:'cobaltage' said:
QUOTE
This is also one of the fastest cards (if not the fastest) in our IOmeter I/O testing. This is not relevant for those who intend to use the card as a storage device, but running applications or even an operating system off the memory card requires the ability to perform a large number of I/O operations per second. Lexar does the best here.
It seems buying a 4 or 8GB version of the Lexar Proffesional SDHC would be good when using a diffrent OS then the one built in the FW.
For the emulators and other games a cheap but big card in the second slot should be fine.
Thanks for the link.
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I run both my desktop and portable off (expensive 300X UDMA) CF cards, as a poor mans SSD.
On the desktop, OS and apps are run from the 4GB CF, and data is stored on regular HDD. Swap is turned off, it's got 4GB of RAM and I never come close to using that. System is incredibly snappy, never chugs and is as responsive as my Amiga was back in the day
On the laptop, OS and data share the CF. Swap is again turned off. Write speed here is less of an issue - but it's actually quicker than the 4200rpm 1.8" drive that was originally in there. System's as responsive as the desktop, with a massively slower processor.
Virtually nil seek time and plenty of RAM to cache writes makes for a really nice system.
On the desktop, OS and apps are run from the 4GB CF, and data is stored on regular HDD. Swap is turned off, it's got 4GB of RAM and I never come close to using that. System is incredibly snappy, never chugs and is as responsive as my Amiga was back in the day
On the laptop, OS and data share the CF. Swap is again turned off. Write speed here is less of an issue - but it's actually quicker than the 4200rpm 1.8" drive that was originally in there. System's as responsive as the desktop, with a massively slower processor.
Virtually nil seek time and plenty of RAM to cache writes makes for a really nice system.
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now that is the spirit! i cannot afford switching off vmem, though, as that mini is .5GB-equpped, and that is not much for osx and the services i run there.'cools' said:I run both my desktop and portable off (expensive 300X UDMA) CF cards, as a poor mans SSD.
On the desktop, OS and apps are run from the 4GB CF, and data is stored on regular HDD. Swap is turned off, it has got 4GB of RAM and I never come close to using that. System is incredibly snappy, never chugs and is as responsive as my Amiga was back in the day
On the laptop, OS and data share the CF. Swap is again turned off. Write speed here is less of an issue - but it is actually quicker than the 4200rpm 1.8" drive that was originally in there. System is as responsive as the desktop, with a massively slower processor.
Virtually nil seek time and plenty of RAM to cache writes makes for a really nice system.
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Yeah sub 1GB you need swap to run any kind of modern desktop + apps.'darkblu' said:
I get very frustrated on a 512MB machine
Just check out ED's video, where he launches ScummVM, and then DOTT. Could it be any quicker?
A lean OS running from solid state is wonderful.
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