Wobbling down the street is Dan 'Miracle' Rutter's cart, packed to the gunwales with fixes, potions, lotions and medicines. Is there one for you, we wonder? If there is, and you're not afraid of weird smells and side effects, then you could win the wonderful Logitech MX700 mouse.
IOOTM: Predictably unreliable
I: My PC keeps resetting for no reason. It doesn't shut down or anything, it just resets like hitting the reset button.I've got a feeling it's a software problem, but I'm not sure. It only does it when I'm actually using the PC -- if I'm away from it, it doesn't do it. Also, I'd like to know how much my 400W PSU can handle, just in case it's that causing the problem. I've got a Palomino Athlon XP 1800+, Gigabyte GA-7VAX mobo, Seagate 80GB 7,200RPM HD, CD-ROM, three 12V fans, Volcano 7+, two 512MB sticks of PC2700 DDR RAM, and a RADEON 9000 PRO, running on WinXP Pro. I'm planning on putting in another six 12V fans (please don't hit me).
James
O: Random resets are a pretty common problem, which can be caused by a number of things. It's probably not a software problem, though.The number one suspect in cases like this is always the power supply. A 400W PSU should have no trouble at all running a system like yours -- a good 300W PSU would be fine, for that matter, though maybe not if you install all of those extra 12V fans. But any PSU can develop problems, and there are lots of lousy PSUs out there with impressive power ratings.
The first thing to try is better cooling, because trying that doesn't cost anything. An overheating CPU (or other component) can cause semi-random crashes and hangs. So take the side off the case, point a desk fan in there, and see if the problem goes away. If it does, then your CPU cooler isn't properly fitted, or your case ventilation is lousy (not enough fans, clogged fan grilles, awful cable layout...), or something's covered with a blanket of dust, or your video card or motherboard north bridge chip cooler is dying.
The next thing you can try that doesn't cost anything is yanking inessential components. There's not a lot you can do here, with an integrated mobo like the 7VAX; it's got built-in sound and networking, and you don't have a bunch of extra cards and drives. Just the same, you can disable integrated peripherals in the BIOS, and try just one stick of RAM, and then just the other one, and you can unplug your CD-ROM drive.If the above steps don't help, then get yourself a nice boring brand name 300W or higher PSU -- an AOpen, say -- and swap it in. There's a good chance that this will solve the problem. Even if it doesn't, a spare PSU isn't very expensive, and is a handy thing to have.
If the problem persists, then it might be the RAM. Even if you still get resets when you're using either memory module singly, it's possible that they're both bad. Buy or borrow a known-good module and try that by itself.
If none of this helps, the next step is swapping out the motherboard.
Ultra drives
I: I am looking to create the ultimate system, and I have been looking at the Gigabyte GA-8KNXP Ultra. Ultra320 SCSI is included on the board, and I was wondering if SCSI has considerable advantages when it comes to gaming because of its speed? Also, current normal PCI slots have a peak bandwidth of 133MB/s; is that a limiting factor if you install a SCSI card in one?
Toby Roberts
O: SCSI super-drives aren't a good choice for desktop machines. A high-priced 15,000RPM SCSI hard drive may well load a big fat game slower than a commodity 7,200RPM drive. This is because SCSI server drives top out at capacities well under 100GB, while commodity drives with capacities well above 200GB are commonly available.
If you've got three times as much capacity, three times as much data passes under the heads per second. That triples your sustained transfer rate, all other things being equal. So a 15,000RPM 73GB drive is only mechanically capable of 61 percent of the sustained transfer rate of a 7,200RPM 250GB drive.
The SCSI drive has superior seek speed, because of its faster-moving head assembly and reduced rotational latency (time for the disk to spin around so needed data comes under the heads). But that often won't save it, for single-user desktop purposes.
The big deal about fast SCSI drives is that they're more reliable (provided you keep them cool) than commodity drives, and can relatively easily be built up into a big RAID array with much better performance than any single drive. For desktop users, though, they wouldn't be an obviously superior option even if they cost the same. Which they don't -- high spindle speed SCSI drives are five to ten times as expensive per gigabyte as 7,200RPM IDE models.
As you say, regular 32 bit, 33MHz PCI doesn't have bandwidth anything like that of Ultra320 SCSI. Plain PCI's ceiling is 133 million bytes per second, which is only 127 1,048,576-byte megabytes per second. Each individual PCI slot doesn't get its own 127MB/s, either; the whole PCI bus shares it, with plenty of overhead. Even if you only install one card, you're still sharing bandwidth if you've got any ATA (IDE) devices; they transfer data over the PCI bus too.
64 bit PCI ('long' PCI slots, which you won't see on many boards not meant for servers) is inherently twice as fast as 32 bit, and can be twice as fast again if it's running at 66MHz, and twice as fast again if it's running at 133MHz. 64 bit PCI at 133MHz is 'PCI-X', which has plenty of bandwidth for even quite serious drive arrays. But you only get that performance if everything connected to the bus is capable of running at its full speed; you can't mix in any slower cards and maintain full speed.
CD speed redux
I: In your reply to the 'MUST...GO...FASTER' I/O letter in Issue 31, you have your information wrong regarding the actual spindle RPM of a CD at 52x.You state that at 52x, a CD is spinning at 10,920RPM. However, I have read in another computer magazine that it's actually about 16,000RPM faster. That was based on work by a Swedish researcher by the name of Jörgen Städje. According to that article, a CD at 52x is in fact spinning at about 27,000RPM, and in fact it's at this speed or just above when they decide to explode.Further information regarding this topic can be found at http://www.qedata.se/e_js.htm .
Bradley Parr
O: The CD and DVD overspeed pages on that Website don't exist any more (well, they're 'by request' only), but archive.org still has one of them:http://web.archive.org/web/20020222010535/http://www.qedata.se/e_js_n-cdrom.htmIf you read this carefully, you'll note that Jörgen's not saying what you think he's saying. He's explaining that if 52x drives spun at 27,500RPM, discs would routinely fail. But they don't.
The original '1x' CD-ROM drives worked the same way as audio CD players, varying the rotational speed as the read head moved outward across the disc. CDs and CD-ROMs are recorded from the middle outwards, with a constant data rate per unit length of track, so to maintain a steady data rate (which you need to do, for audio), you have to spin the disc faster for the inner tracks than for the outer ones. About 539RPM for the innermost point; about 210RPM for the outermost one (if the disc is full; if it isn't, the head will never get out to the edge).
This is called 'Constant Linear Velocity', CLV, because a constant length of track passes
Issue: 137 | June, 2012