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Pioneer DVD-305S

  December 27, 2000 Author: Tim Zakharov  
Special thanks to* for providing the evaluation unit.

* Remember, mention when ordering from HyperMicro and receive FREE shipping!


Back on September 7th of this year, we brought you the web's first look at Pioneer's new DVD-304S, the fastest-rated SCSI DVD-ROM drive. During the course of testing this drive we came across some potentially serious issues. First, there were difficulties reading CD-RW media. We also uncovered a digital audio extraction issue similar to what we had experienced with the Pioneer DVD-115, and we found that we could not reach the advertised 10X DVD read speeds. We promised our readers that we'd look into these issues and report back any new findings. Unfortunately, no solutions were found. Our communications with Pioneer could not shed any light either. Eventually, the issue appeared to have been forgotten.

Fast-forward about 3 months... Hyper Microsystems offered to send us a Pioneer DVD-305S. Unfamiliar with the model number, we checked Pioneer's website, but the latest drive they had on their product page was the DVD-115, itself 8 months old. After mentioning the 305S in our December 8th Headline, we received an email from a reader who provided us a link to Pioneer's European website detailing the DVD-305S. From there, we hopped over to Pioneer's Australia website and found it listed there as well. Meanwhile, a reader on our BBS claimed the model number might be "invalid." Pioneer could not provide us with any new information besides confirming that it was indeed a new model.

Today we're still left with a mystery on our hands. Why do the 304S and 305S have nearly identical specs? Perhaps a thorough examination of the 305S will yield some clues. Come along as we investigate.


Our first hint at the difference between the 304S and 305S comes from Pioneer's Australia site. This page shows us that the 305S is labeled "new" while the 304S is labeled "discontinued." According to the spec sheets for the 304S and 305S, the only apparent difference is in the DVD-ROM access times--the 305S is rated at 95 ms while the 304S is rated at 100 ms.

The remainder of the vital specs: an 80 ms CD-ROM access time, a 512 kb buffer, and an industry-standard 1-year warranty. Digital audio extraction speeds are not listed in the specifications for this drive, but previous Pioneer units have typically been rated at 12X CLV. The Ultra-SCSI interface remains unchanged over previous generation units, as does the lack of a digital audio-output. It appears as if Pioneer reserves the digital-out only for their slot-loading ATAPI models. The street price for this bare OEM model is about $150.

In areas of heat and noise, the 305S does okay. Subjectively, we found the full-rpm hum of our sample to be acceptable--pretty typical for a 40X CAV reader. Seeks, on the other hand, were not obtrusive at all. We did find, however, that the 305S became quite warm during stress tests. It took about 20 consecutive runs of CD Winbench 99's access time test to get the drive to its peak temperature, so we're not too concerned with the drive running overly hot under normal conditions. Finally, during DVD movie playback the drive was nearly silent and was barely warm to the touch.

Continue along with us as we examine the 305S' performance...

For an overview on methodology, click here.

CD-ROM Performance Results

Low-Level Measurements

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In our sustained transfer rate (STR) test, the DVD-305S starts off at nearly 22X on the inner tracks, continuing on to finish at over 44X by the outer edge of our test CD. This is 11% faster than specifications. Notice how similar the results are to Pioneer's DVD-115. However, these results are 8% faster than its predecessor, the DVD-304S, and 10% faster than its main competitor, Toshiba's SD-M1401.

Average random access times come in at just over 87 ms, about 8% slower than Pioneer specifies. Comparatively, the Toshiba's 75 ms result is significantly faster. Again, notice how similar this result is to the DVD-115. Will this trend continue? Let's find out.

CD-ROM Winmark 99

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In the CD-ROM Winmark test, quick access times generally play a strong role in high scores. The 305S' score of 1618 is the best we've measured for a DVD drive by a tiny margin and the 3rd best score we've ever measured. Competitor Toshiba is over 20% slower in this test. The DVD-115 trails by 1.5%, while the 304S is 10% back. A trend appears to be forming.

File and Disc Copy

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Our file copy test, which involves copying a single 634 MB file to HDD, is STR-intensive, since by definition no random accesses can occur in a single file transfer. The DVD-305S completes this copy in 2:18, again right about equal to the DVD-115. The DVD-304S trails here by 12%, while the SD-M1401 lags by 10%.

Our disc copy test is more representative of typical CD copies, as our test disc holds a variety of files within folders. This means that random access speeds will contribute to overall performance in this test. The DVD-305S completes this test in 2:46, which puts it 9% ahead of the SD-M1401. Continuing our comparison with the DVD-115, we again have results nearly equal between the two Pioneers. The previous-generation 304S trails the 305S by 7% here.

Digital Audio Extraction

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You may recall in both our DVD-115 and DVD-304S reviews, we encountered an odd problem with audio extraction. When extracting an entire audio CD in one session, DAE speeds pulled away from the 12X CLV (constant linear velocity) specification. Instead, we measured CAV (constant angular velocity) extraction rates. The actual problem involved the drive suddenly spinning down mid-extraction, causing a pronounced dip in the graph. What this created was an audible "pop" in the extracted audio that corresponded with where the dip in the graph occurred.

Briefly, when CLV is implemented, the drive varies rpm to keep the transfer rate constant across the CD- rotation speeds are higher when reading from the inside of a CD, and gradually reduce as reads move toward the outer edge. As such, more strain is put on the drive motor when CLV is used. When CAV is implemented, however, the drive's spindle motor spins the disc at a constant rpm, which leads to a varied transfer rate: At the innermost tracks of the disc, transfer rates are slower; as the drive's pickup moves towards the outer edge of the CD, transfer rates increase.

Our DVD-305S evaluation sample shows extraction rates nearly identical to what we've seen in the DVD-115. Unfortunately, we also were able to duplicate the popping sound and correlate it with the dip in the graph. To illustrate, click here to listen to the affected area, then click here to hear what it ought to sound like. The dip and resulting "pop" consistently occurred at about the 24th minute of our test CD-DA, but the dip varied in location when different audio CDs were used. For example, we inserted a brand new CD-DA that was shorter than our test disc (51 minutes vs. 65 minutes) and the dip occurred at the 20-minute mark.

It appears as if there may be either a firmware or spindle motor problem. The fact that similar problems were uncovered with two other Pioneer models eliminates the possibility of a damaged drive. If it's a firmware problem, perhaps the instructions to switch to CLV are not being sent to the motor when one sets up to extract an entire audio CD in a single session. If it's a motor problem, perhaps the motors have some defect that prevents them from gradually reducing rpm in conjunction with the pickup moving outward along the disc. Perhaps the issue lies somewhere in between or elsewhere entirely.

It should be emphasized that this issue was only producible when we attempted to extract an entire audio CD in one session. The problem was not producible when extracting single audio tracks. In such scenarios, extraction rates stayed in the 12X range, even when extracting the final tracks near the outer edge of the CD-DA (where CAV extraction rates would normally shine). This suggests that instructions are being given by the firmware to extract at 12X CLV when extracting individual tracks, but are being ignored or interfered with somehow when all tracks on the CD are selected to extract in one session.

How serious this issue is depends largely on how seriously one takes their audio extraction, as well as how one goes about it. This problem will only affect those who rip entire audio CDs to HDD. If this sounds like you, you may well be affected by this issue. Even then, the problem is limited to a single "pop" at roughly the 20-24th minute inside of each audio CD. Otherwise, you likely will not notice any quality issues. CDSpeed99 and CDDAE99 both claimed perfect extraction, and our informal listening of various tracks uncovered no other quality issues besides the one noted above.

CD-R Media Compatibility and Performance

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Pioneer's DVD-305S reads our 12X TDK CD-R at speeds identical to pressed CD reads. This keeps the 305S at the top of the list compared to the competition. There were no compatibility issues with reading our 12X Imation 80-minute CD-R.

CD-RW Media Compatibility and Performance

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In our review of the DVD-304S we encountered a serious issue with reading CD-RW media. Basically, as long as sequential reads were done, there were no problems. But as soon as random accesses were thrown into the mix, we'd immediately get read errors and blue screens from Windows. We are happy to report that this problem is not present in the DVD-305S. Transfer rates with our Verbatim CD-RW test disc were 16X at the innermost tracks, increasing to 32X at the outer tracks. Again, we have results nearly identical to Pioneer's DVD-115. The 305S was able to read 4X CD-RWs from Verbatim, Memorex and Sony without problem, as well as our high speed CD-RW from TDK. In all cases read speeds were 32X CAV.

By now we've gathered enough evidence to hypothesize that Pioneer's DVD-305S and DVD-115 share some internal parts and perhaps some firmware algorithms as well. In just about every read test we use, the two drives yield performance figures nearly identical to one another. How will they compare in our DVD tests? Follow along as we continue our testing.

DVD-ROM Performance Results

Low-Level Measurements

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When we tested the 10X-rated DVD-304S, we found that transfer rates topped out at just over 8X, and then reduced over the final 1 GB of our test DVD. However, if one looks at the numbers without examining the graph, this gives the impression that the drive is capable of less than 7X DVD. In reality, the average overall transfer rate, 6.5X, was only about 15% slower than expected-not the 30% difference one would presume just by looking at the results at the outer edge. The DVD-305S does much better in our measures, with average overall transfer rates of over 7.1X. A look at the transfer rate graph shows that, while there's still a bit of a dip at the end of the graph, it's far less pronounced than it was on the 304S. We now see speeds over 9X being achieved. To check ourselves, we tested informally with a few other DVDs and found some that would not show this dip at the outer edge. These discs finished at about 9.6X and averaged in the area of 7.3X. This confirms that the 305S is performing very close to specifications. As far as we're concerned, the DVD issue we found in the 304S is now gone.

Granted, this discussion only matters to those who actually use their DVD drives for reading application DVDs (games, encyclopedia software, etc). DVD movies still play back at only 1X, so if all you will use your drive for is watching movies, don't place much emphasis on getting the fastest DVD read speeds around, as they will be wasted. Previous generation 4-8X units will do just fine and cost much less if you can find them still being sold.

CPU utilization at 1X as measured by DVDSpeed99 was right at 9%. This is equal to what we measured for Toshiba's SD-M1401 and 1% better than the 304S.

Subjective Playback Observations

In watching portions of two movies (Twister and The Matrix), we found no quality issues during playback. Remember, DVD movies play at 1X, so just about any modern DVD-ROM drive will do a good job playing movies, provided it is installed in a system with decent CPU speeds (greater than 300 Mhz) and sufficient memory (at least 64 MB, preferably 128 MB). Systems with hardware-based DVD decoders can get away with slower CPU speeds.


In our original review of Pioneer's DVD-304S, we found three issues which kept us from recommending the drive over its main competitor, Toshiba's SD-M1401. These were, difficulty reading CD-RW media during random accesses, digital audio extraction quality issues, and lower-than-expected DVD transfer rates. Since the DVD-305S has nearly identical specs to the 304S, we're led to believe that the introduction of the 305S is primarily to address these and perhaps other issues. For the most part, the 305S succeeds. The worst issue, inability to read CD-RW media when random accesses are attempted, does not exist at all in the 305S. However, the DAE issue has not been addressed at all to our knowledge. In fact, in all appearances the 304S DAE issues were just traded in for the DVD-115's DAE issues. Lastly, it appears as if the DVD transfer rate issue has been resolved.

The Safe Buy Award

Simply put, this designation means we'd purchase this product without regret. Sure, there may be a slightly better, slightly faster, and/or slightly less-expensive model from a competitor, but you can't go wrong with this particular unit. This award is applicable, of course, to all units at the top of their class, but also applies to units that, though not quite best-of-class, provide a strong showing nonetheless. Is this enough to dethrone the Toshiba SD-M1401? We feel it depends on how seriously one takes the DAE issue. In our view, this issue is limited and in many cases may never come into play for most users. We understand the needs of serious audiophiles, though, and cannot recommend the 305S to such folks if they plan to use this drive to extract digital audio. To most others, though, we have no qualms with recommending the DVD-305S over the Toshiba SD-M1401. It is a superior CD, CD-R, and CD-RW reader, and DVD transfer rates are about equal to those of the Toshiba.


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