After reading the topic on "partioning scheme" here i have decided i want to partition my C3000 to give me about 2GB of internal space for program installation and leave 1GB of FAT space to be used for USB mass storage when conecting to Windows and such. I am not sure exactly how to partition this off but that is left for another topic. What i would like to know is if the 4GB MD is faster/slower to read and write from than what a 1GB SD card would be. I want to use alot of this space to install X/Qt and apps on. If the SD card will give me significantly faster read and write times then there is not much reason in doing this except for being able to eject your SD card and all your programs will still run.
I think i will still partition my drive, but i would really like to know if one is faster than the other. If some one knows how to just test this with something like the "dd" comand then i can just test it myself and post my results. I saw a post along time ago about testing the speed of SD cards but i did not find it so i am not really sure how to test it myself. Thanks for all the help.
Also Neuroshock if you read this post, do you know if the retail version of the 6GB 1. Seagate MD has faster read/write and access times than the original Hitatchi MD. Also what about power consumption?
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Sure. Let me make a few definitions about performance before I comment so I make sure we're all talking about the same things. The speed issues that affect all this are:
Read Access Times (How long it takes the storage medium to find the data it's trying to read- Rated in Milliseconds),
Write Access Times (How long it takes the storage medium to actually start writing the data to storage after the request is issued - Rated in Milliseconds), and
Data Throughput (The amount of data the storage medium can move from/to itself once Access time is over and data actually begins moving - Rated in Megabytes per Second).
To avoid confusion you will also find references to two kinds of Data Throughput –
Burst (How much data the device can deliver to the system in very short or initial data transfers) and
Sustained (How much data the device can deliver to the system from the storage medium for extended periods of time.)
Please note that in Flash Memory (and therefore all SD and MMC cards) there is effectively NO Read or Write access times because since they have no major moving parts they don't have to worry about spinning up or moving the head across the physical platter to get to the info etc. like Microdrives Do. Pretty much Data Throughput is the only performance issue I'm addressing that affects SD and MMC cards.
There, that should cover the basics.
Let's do 4gb original embedded Microdirve vs. the Retail versions of Hitachi Microdrives (4 and 6gb versions) first.
The whitepaper specs of the 4gb OEM version of the drive are almost identical to the published Specs on the Retail 4 and 6gb versions, however, in performance tests on the microdrives in Real World benchmarks the retail version outshone the OEM version in my C3100 by about 10%-18% in all tests I have conducted. My hunch is that this is due to Sharp modifying and hard-coding some firmware options on the 4gb drives for reasons I'm not currently aware of. I'm still trying to find a way to browse to the Firmware and Hardware's configs of the controller on the MicroDrive itself but haven’t succeeded yet. But regardless of the reason for the poorer performance if you upgrade it to the Pexagon Incorporated retail versions of the Hitachi Microdrive then you will get SOME performance increase, but probably not enough in most situations for the average user to feel compelled to spend $100-200usd that it costs to buy them at the time of this writing. Remember just because the Drive itself is possibly up to 18% faster - the speed of your system as a whole will probably increase about only about 5-6% MAX. So the big picture benefits are pretty marginal in my opinion unless you’re just a performance Zealot like myself.
I have not tested battery drain issues between the two drives, but it should be insignificant as their wattage seems to be identical. Also the battery drain rate issues that affect us here are all Microdrive issues and so are applicable to both evenly. However in contrast if you wish to compare battery life between the Microdrives and Sd cards the Sd card will win hands down every time since it has no moving parts.
As for deciding whether to install X/Qt on Sd or Md it ends up being a personal judgment call in the end. Perhaps these facts can guide you into forming an educated decision on performance impact of the choices you have:
Sd performance is limited on the Zaurii because Sharp forces us to run in MMC compatibility mode. Since Access times are insignificant this simply means in real world terms that your Data Throughput is going to be MUCH lower using your SD card in your Zaurus than what most new, 1gb SD cards are truly capable of. Also if you haven't already bought a 1gb Sd card, then consider buying one that is at least rated around 10x-12x as you will see data throughput increase by doing so. Don't pay a lot of extra money to buy an Sd card that is way above 10x because it will gain you NOTHING further in speed increases.
Be aware that The CF slot on the Zaurus has no such performance restrictor and therefore outperforms SD cards neatly when it comes to Data Throughput.
As mentioned in my term definitions the Sd card has access times that are for all practical purposes nonexistent so whenever the system asks for Data movement the Sd card can begin transferring the data RIGHT NOW unlike the Microdrive which has to both spin up if it's not already spinning and move mechanical parts to get to the right place the data is stored on the platter. So SD has an edge in Access times.
Please know right up front that because of the software AND hardware sides of the Sd card issue as Sharp has implemented them in the Zaurus, Data Write Throughput is always much slower than Data Read Throughput. This makes the SD card a fairly decent place to install programs to since there is much less writing to, than reading from, the storage medium once the programs are initially installed. This also makes Sd cards a seriously inferior place to install a Swap Partition or Swap File as compared to ANY CF card (either Microdrive or Flash Memory) since this has a LARGE amount of Data Writes 100% of the time that it is being used by the system because your physical memory has been exceeded.
Quick Recap of Sd card pro's and con's:
Pros:
----- Sd = MUCH faster at finding where to get/put data on the drive (Access Times) than Md's.
-----Sd = A fairly good place to install Programs.
Cons:
----- Sd = Write Data Throughput is always lower than Read Data Throughput.
----- Sd = These cards seldom live up to their speed potential on Zaurii because Sharp has shackled us with MMC compatibility mode in it’s Sd implementation.
Microdrives:
I’m specifically speaking about the Hitachi 4gb and 6gb Retail Version Microdrives.
Data Read Access times and Write access times, unlike the sd cards on Zaurii, perform equally in basic Real World terms. As mentioned earlier it takes much longer for Microdrives to begin Reading or Writing data because the physical parts must travel to where they need to be. Always try to remember that Microdrives are quite literally tiny Hard Drives like what you use in your Desktop computer and suffer/benefit from the same issues they do.
Data Throughput in most Microdrives will knock the snot out of any Sd card in a Zaurus because of the MMC compatibility issue. Current Microdrives have EXCELLENT data throughput when compared to a CF Flash Memory cards as well. Only the fastest and most expensive CF Flash Memory cards have higher Sustained Data Throughput than these Microdrives. As far as bang for the buck Microdrives are a faster/better way to go for equal amounts of storage when compared to CF Flash Memory cards.
Microdrive Spin-up time is an important consideration when comparing Sd vs. Md. On a cold data call the Microdrive will be powered down to save on battery drain and the drive has to spin the platter up to speed before it can begin to even start the Data Seek. This is mostly noticeable when you first click on a program that is installed on a Microdrive as it has to wait for the disk to be spun up if it’s not already. On a C3000 you should be used to this.
Data Seek (both read and write) times are MUCH longer than Sd cards not because of the device format (CF vs. Sd) but rather because the Microdrives are majorly mechanical and parts take time to move around- Sd cards are always Flash Memory and never suffer from this limitation.
Facts concerning Pro’s of Sd cards and Microdrives. (quick recap):
Sd Pro’s:
-----Sd cards have basically Data Access times of Zero as compared to the much greater Access times of the Microdrives.
-----Sd cards drain the battery MUCH slower than Microdrives do.
----- Sd cards do not have to spin-up when they enter “sleep†mode.
Microdrive Pro’s:
----- Data Throughput (both burst and sustained) are much better than Sd cards on Zaurii.
----- Microdrives are usually MUCH less expensive for the equivalent amount of storage on an Sd card.
Now those are the cold facts. But like most things when you implement them into Real World situations the facts on paper can be very misleading.
Strategies to get the best out of and from both technologies:
Everyone always harps on the spin-up and Data Access time penalties when dealing with a Microdrive in a Zaurus. The Data Access time even though it is Huge when compared to Sd cards are still not a huge impediment. This is because the Data Access time on the Microdrives is about 12 milliseconds. 12 Milliseconds is only a tiny part of a single second. Most users simply don’t notice the cumulative impact of this in Real World applications. A better way to describe Data Access on Sd and Microdrive mediums would be to say that while Sd cards have NO Data Access delay, Microdrives have a tiny Data Access Delay. That would be keeping the perspective of the issue more true to life.
The Spin-Up issue can also be minimized depending on usage. The concept here is to try to get things setup so that the Microdrive has to Spin-up from a stationary position as SELDOM as possible. Remember, if it’s already spinning then this penalty simply doesn’t exist! To do so you can apply a strategy that seems to be contradictory to normal performance usage – You try to run the installed programs AND have the Swap File/Partition all on the same Microdrive. If you do this then any data call that is made will go to the Microdrive and the Microdrive will stay spun up more of the time. The fact that you would also be using this in a C3000 where much of the OS and other programs are also run from the Microdrive then my guess is in Normal Usage the Microdrive would probably VERY seldom get caught spun down during high intensity program usage like X/Qt. In Desktops you wouldn’t want to do this because it would degrade Swap performance, but Desktops don’t face the massive spin-up issue to begin with.
Please note that this very same strategy will NEGATIVELY impact your battery life since the drive will stay spinning more often. It’s something to bear in mind.
The memory buffer that is installed on the Microdrive also helps minimize the raw impact of Data Access, Data Throughput, as well the Spin-up issue.
The bottom line of all this in my estimation is that Microdrives perform MUCH better over all than people give them credit for if you use a good Strategy along with them. Just about any benchmarking you wish to do will confirm my overall opinion when applied to Microdrives that are being used in Zaurii with resource greedy programs like X/Qt.
So here’s my final advice:
If you’re most worried about battery life then install X/Qt and it’s apps to an Sd Card that is rated at 10-12x speed or more. You should also consider formatting the Sd card with ext2/3 in order to keep from having to use a loopback device and taking the associated performance hit. This will make the card unusable/unreadable in Windows environments. You should then make a Swap File or Partition on the Microdrive and enable it only when your physical memory in your Zaurus is depleted.
If you’re concerned only about performance issues or are much more concerned with performance than you are battery life then choose to upgrade to a Retail 4gb or 6gb Microdrive and Partition it similarly to how I finally ended up doing in the other post you referred to. (Add an ext2/3 extended partition and a Swap Partition in another extended partition). PLEASE NOTE that my instructions and success were based on the fact that I had a C3100 rather than a C3000 so proceed with care. This will be the least optimal solution for battery life. I think you’ll be surprised and discover that it won’t eat as much battery duration as you would initially think though.
Of course there are several variations you could go with in between those but these are the two extremes.
If you TRULY want to go the PURE performance route then replace the interior Microdrive with a 4gb or larger High Performance Flash Memory card, and partition and use it identically to the pure Microdrive choice. Good cards for this would be the current Lexar 80x 4gb Professional Series CF card or the Newest flamethrower that Sandisk has thrown on the market in a 4gb capacity or larger- I can’t vouch for the Sandisk, but my 80x 1gb Lexar CF card is very impressive from a performance perspective indeed. Just make sure you choose a CF Flash Memory card with the same or better Sustained Data Throughput than that of the 6gb Hitachi Microdrive. This is EXPENSIVE but the FASTEST option right now. It should also have much better battery life than compared to the equivalent Microdrive solution and should be fairly equivalent to the battery life expected when using the Sd card choice.
Here are a few links to the products discussed in this post and some links to some products I can recommend for performance and reliability:
Hitachi Microdrive 6gb General Specs- (the 4gb card is identical in every way except size)
[a href=\"http://www.hitachigst.com/portal/site/en/menuitem.a994b57654279b5daa67bca4bac4f0a0/]http://www.hitachigst.com/portal/site/en/m...67bca4bac4f0a0/[/url]
Hitachi Microdrive 6gb Datasheet Specs- (the 4gb card is identical in every way except size)
http://www.hitachigst.com/hdd/support/micro/3k6.htmThis link has a link to a comparison chart of Lexar’s CF Medium. I can personally recommend the Lexar CF Professional 80X CF cards. They work beautifully in Zaurii and are screaming fast. Also note that Lexar’s ratings (80x in this case) are the minimum SUSTAINED data rate rather than the BURST data rate that many CF card manufacturers use to identify their speeds. Using Burst data rates to class a CF card is just simply deceiving imho. Lexar’s honest. If they claim it will go 80x, then it will. Here’s the link:
http://www.lexar.com/digfilm/compact_flash.htmlHere’s the detailed view link to the Lexar 80X Professional Series CF card:
http://store.lexar.com/?category=21&subcat...d=CF4GB-80-380EThis is a similar link to Lexar’s SD Platinum card lineup. I can personally vouch for the 40x Platinum card and the 80x Professional Sd card (which is elsewhere on their website.)
http://store.lexar.com/?category=21&subcat...id=SD1GB-40-231Here’s a link to what is supposed to be the fastest Zaurus compatible 4gb CF card on the market today (133x). I’ve seen where others have successfully used this card but have never used one myself. This link is just offered for research purposes I cannot speak for its compatibility or performance.
http://www.sandisk.com/Products/Item(1182)...tFlash_4GB.aspxI think that about covers it – If you have any specific questions just give me a yell and I’ll try to help if I can.
Cheers!,
-NeuroShock
