Apple's MacBook Pro with 128GB SSD: Performance and Battery Life Investigated
by Anand Lal Shimpi on April 15, 2008 4:20 PM EST- Posted in
- Mac
Better Battery Life? Not Necessarily
Hitachi lists the read/write power of the 5K250 that comes in the MacBook Pro as 1.7W on average. Idle power is even lower obviously. Memoright doesn’t provide similar specs on the MR25.2-128S but the top of the drive already tells an interesting story: 600mA at 5V, or 3W. It looks like in the quest for greater performance, the Memoright drive actually consumes more power than a mechanical disk drive. While Flash memory should have no problems running at 3.3V, I suspect that the FPGA and PATA-SATA bridge both require a 5V input which is why the drive uses 5V power from the SATA power connector and not 3.3V.
With potentially greater power usage, it doesn’t look like we’ll be gaining any battery life from the SSD. To confirm, we ran the same battery life tests we have been using in our recent MacBook Air and MacBook Pro reviews:
| Battery Life in Hours (Higher is Better) | MacBook Pro (Hitachi 5400RPM) | MacBook Pro (Memoright SSD) |
| Wireless Internet Browsing + MP3 Playback | 5.13 hours | 5.0 hours |
| DVD Playback | 3.88 hours | 3.58 hours |
| Heavy Downloading + XviD Playback + Web Browsing | 3.38 hours | 3.37 hours |
The wireless browsing test shows the mechanical disk offers a slight battery life advantage of around 8 minutes over the SSD system. While losing 8 minutes of battery life isn’t tremendous, the point is that battery life doesn’t improve any.
The DVD playback test paints the SSD’s battery life in the worst light; the system equipped with a mechanical disk outlasts it by around 8%. In the case of the MacBook Pro, that 8% translates into 18 minutes of battery life.
Our final test shows no difference between the mechanical and SSD drive.
It’s worth noting that how the SSD fares really depends on the reference point. Had we used an older, higher power mechanical disk the situation might have been different. A quick look at the specs for the 7200RPM drive that Apple offers on its MacBook Pro shows that despite a faster spindle speed, power consumption would increase to 2.3W, still lower than the Memoright drive.
Memoright doesn't list more detailed power specs for its drive so it's possible that the difference is closer, but without a doubt the SSD doesn't offer any power advantages in this case. The battery life tests provide an important distinction, as we saw battery life increase in the MacBook Air but decrease here. It just goes to show you that simply switching to a SSD won't necessarily improve battery life, it depends on what you're switching from and what you're switching to.
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Alexstarfire - Wednesday, April 16, 2008 - link
Efficiency != performance. You know that, right?JarredWalton - Wednesday, April 16, 2008 - link
Yeah. Using a custom IC means you don't have any extra transistors wasting space and power. An FPGA can do the same thing as a custom IC, but you usually have more gates available than you actually need.nubie - Tuesday, April 15, 2008 - link
I was under the impression that SATA used more electricity than PATA, no mention of that?We are going to need a dedicated low power mode for the chipsets and the SSD's
I wouldn't be surprised if these are all switched to a Mini PCIe card when this is mainstream. The added bulk, price and inefficiency of these in a 2.5" form factor is just plain dumb, besides, let it communicate over PCIe, then you wouldn't need to have a PATA-SATA etc interface.
mindless1 - Friday, April 18, 2008 - link
1) It would be very risky to design a laptop that didn't support 2.5" drives, a lot of the market isn't going to pay $4000 for their hard drive.2) You are obviously wrong about (significant) added bulk, that size is what allows the number of flash chips to reach capacity, the controller to improve performance, and the supporting electronics onboard. Of course there is a bit of space non-electronically *wasted* but so it goes with modular parts. When flash density increases again you could have smaller form factor with same capacity or you could have higher capacity. Also, a well optimized controller should parallelize access to the chips so more chips = better performance.
3) SATA vs PATA power consumption is not necessarily a difference enough to be significant in total device power consumption, although in this case with a PATA SATA bridge chip there is a small (probably under 50mA) consumption by that bridge.
4) You suggest comm over PCIe would be significant, that you wouldn't need PATA to SATA, but you would still need intermediary controller. Remember that SSDs are not developed for only one notebook, the market for a $4000 device is limited enough already so supporting the largest # of systems reasonably possible will help drive down prices.
5) What happens when you keep packing more and more active parts into a smaller space? Power density goes up and you then either need a fan or elaborate heatsinks scattered around and a lifespan degradation of other parts from running at higher temp. Not what people want when paying $5000 plus for a laptop.
In the end, SSD is still in it's infancy, think back to the improvements in mechanical drives made from the beginning until now. Ultimately if space savings becomes priority #1 they will just integrate the controller and flash chips onto the mainboard, forgoing the PCIe mechanical interface and parallel PCBs, that space consumption altogether.
Personally I think we need a new memory format similar to Compact Flash, with robust pin connectors, easily slotted and removable, and native SATA300 support. Next we need a portable Windows, so switching from your laptop environment and files to your desktop is just a matter of pulling card out of slot and plugging into the other system - or any other PC in the world for that matter. The crude precursors of this are already seen in mobile apps on USB thumbdrives but to be truely portable the whole OS environment needs be fully plug-n-play not what MS calls PNP.
quanta - Tuesday, April 15, 2008 - link
Last time I checked, even 8 sticks of Corsair Flash Voyager GT (16GB) flash drive cost less than $1000 total. Even with FPGAs and other extra electronics, the $3,819 price tag is a poor price excuse for extra performance. Considering that the drive doesn't even read and write at 8x the speed of Flash Voyager GT, you are better off using the extra cash to get better laptop options for other components.ltcommanderdata - Tuesday, April 15, 2008 - link
It's interesting that although your article mentions at the bottom of page 2 that and SSD would appear as just another hard drive, the DV Nation website lists the system requirements as OS X 10.5 being required. I guess they are just being conservative.I would like the response time of an SSD, but beyond the price, the storage capacity is still a bit constraining, even at 128GB. Personally, now that Fujitsu has announced 320GB 7200rpm 2.5" drives, I'm waiting on Hitachi to release an equivalent to replace my 160GB 5400 rpm Hitachi in my MacBook Pro. If I'm not mistaken Hitachi drives tend to be faster than Fujitsu.
Timothy123 - Tuesday, April 15, 2008 - link
Honda Civics do not depreciate that much, pretty bad example actually. Honda is known for it's high resale value and continued quality through high mileage and the test of time.You should have picked an American car to use in that metaphor, for instance, any car made by Ford or GM would have been a good choice.
A Ford Focus for instance, loses a lot more of it's value than a Honda Civic, hell for that matter, any American car loses it's value quicker than a Honda Civic.
Really really really bad example. Really bad.
xkon - Saturday, April 19, 2008 - link
lol. well... that kind of makes the statement true nonetheless. if the sdd depreciates in value 40% that means it depreciates a lot faster than a honda civic. if they'd chosen say... a dodge intrepid (my neighbor's '03 sold for $3000) or something like that, the depreciation value would be similar or over 40% defeating the purpose of the comment.Googer - Wednesday, April 16, 2008 - link
Tim,What the hell has that got to do with any thing in the article?
strikeback03 - Wednesday, April 16, 2008 - link
I had the same thought about the lack of depreciation on Civics when I read that line. And the fact that half the comments relate to that one sentence is humorous as well.