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Lexar Media solves D1 startup delay  
Tuesday, January 16, 2001 | by
Scott Audette suspected something was amiss when he grabbed his sleeping Nikon D1 to shoot a picture, only to find that the camera would pause noticeably before firing. Though he knew of the D1's 1/3 to 1/2 second startup time, the pause seemed to him to be longer than that. A quick comparison of Lexar Media 320MB 12x CompactFlash cards with another brand revealed that the extended, approximately 1 second pause before the camera would fire was with his Lexar cards only; with a lower-capacity Sandisk card inserted, the pause, while still noticeable, was closer to the camera's startup time spec.

Lexar Media 320MB 12x card

For the Tampa Bay Lightning team photographer and AP stringer, the additional startup time was posing a problem when shooting hockey and other fast moving assignments. This was true especially with his second D1 body, which would almost always be asleep when Audette pulled it to his eye and squeezed the shutter button to make a quick sports action frame.

Audette's recent discovery of the D1 startup delay when higher-capacity Lexar cards are inserted triggered a chain of events that culminated in the Fremont, CA-based company developing a fix earlier today. The fix, promises Lexar, will virtually eliminate the additional startup delay (reducing it from approximately 600ms to perhaps less than 10ms with Lexar's 320MB cards; lower capacity cards, including the 256MB, 160MB and 128MB, will have a proportionally shorter delay before the update is applied), and should be available by week's end as part of a new firmware release for Lexar Media cards.

How the firmware release will make it into the cards of D1 shooters is still being sorted out by Lexar; I will be following up with company representatives on Wednesday and Thursday, and will post a story as soon as Lexar's firmware release plan is finalized. What's certain is that D1 users will soon be able to send affected cards back to Lexar for free installation of the firmware update into the card, though Lexar is exploring other options as well for organizations such as newspapers with dozens or even hundreds of cards in the bags of their D1 photographers.

How the firmware update solves the D1 startup delay

To solve the D1 startup delay, Lexar Media engineers first had to determine what steps the D1 was performing, and what information it needed from the card, during its startup sequence. They discovered two key things:

  • The camera turns off power to the card slot not only when the camera is turned off, but also when the camera goes to sleep. When the D1 is awakened, the card and camera both run through their startup sequence each and every time. Since the camera goes to sleep after no longer than 16 seconds (Custom Setting 15 controls this, and may be set from 4 to 16 seconds), the card slot will be powered down if the photographer does not activate the camera within no more than 16 seconds of its last use.

  • When the camera wakes up, it won't permit the shutter to fire until the card responds to a query about how much space is available on the card, to ensure that it won't fire if the card is full. The camera does not require additional information from the card before deeming it ready for use.

Upon receiving power from the camera on wakeup, the firmware currently in Lexar cards first loads the card's space management code and optimizes an internal table for quicker data writing. This startup routine, says Lexar, is a key contributor to their cards' speedy sustained write speed. The time it takes for the routine to run, however, is directly proportional to the capacity of the card; the higher the capacity, the longer the card startup time. Once this routine is complete, the card then responds to the camera's request for information on how much space is available for photos. With 320MB cards, the delay is in the 600ms (6/10ths of a second) range; add this to D1's startup time of nearly 1/2 second, and the total time the user must wait to shoot a picture is about 1 second.

Solving the startup delay, then, meant changing the order in which Lexar cards run through their startup routine. The firmware update knocks almost the full 600ms off the total startup time of 320MB cards simply by forcing the card to report to the D1 how much space is available before running its own startup cycle. And it does so, says Lexar, without introducing incompatibilities elsewhere, including with other digital cameras, card readers and sundry other electronic devices.

If the firmware update is as effective as promised, it should greatly improve the usability of Lexar cards for shooters that use two D1 cameras at fast-moving assignments, as well as for anyone that routinely has to pull the D1 out of its sleep mode to quickly shoot pictures.

Lexar expects that the firmware update will zap the startup delay with 128MB and larger Lexar cards of any speed rating (i.e. 8x, 10x and 12x). At this time, it's not expected that cards with a capacity lower than 128MB will require an update, because of the relatively short startup time of those cards already. Lexar will update the firmware in sub-128MB cards too, however, if a customer requests it.

Please check this site as the week progresses for details on the logistics of having the Lexar cards that you use with your D1 updated with the new firmware.

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