phd_jacquier@gsbacd.uchicago.edu (11/15/89)
This is a follow up on previous posters about chips pushed beyond their
guaranteed speed:
This summer, SAI SYSTEMS LABORATORIES (SSL) in Shelton CT sold me a
"12 Mhz, 0 wait states. portable AT-286"
Recently i opened it to put in a 287 and saw that they use a SUNTAC 12Mhz
board with a 10Mhz cpu. I had noticed a minor performance difference with my
12 Mhz desktop which i had attributed to possibly a not so well made board.
I called and they stand by it even though they don't tell you anything at
purchase time. Here are some excerpts of the phone call:
Q: " It is not recommended to push CPU's beyond their guaranteed speed.
You should give me a 80286-12 if i paid for a 12Mhz system"
A: " Have you had problems? You have a one year guarantee anyway"
Q: " What if it dies after one year because it's been used at too fast
a speed?"
A: " If there is a problem because of the speed, it's going to happen right
away, not after a year."
etc..etc..
sigh .. give up..
These guys have lie about a practice that is disapproved by the
chip's manufacturer and is not common (hopefully).
The second answer is B.S. as it is obvious that the
effect of overheating is more likely to shorten the life of the CHIP rather
than kill it right away.
BEWARE OF SAI TECHNOLOGIES CHEAP CHIP PRACTICES.
EJ.
PS: Is there somebody from INTEL around to formally confirm that you do NOT
want to push a CPU? It it's the case, then these guys who are
professional pc assemblers are CROOKS or IGNORANT. davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) (11/15/89)
In article <6268@tank.uchicago.edu>, phd_jacquier@gsbacd.uchicago.edu writes: | This is a follow up on previous posters about chips pushed beyond their | guaranteed speed: | [ posting about a 10MHz chip run at 12 MHz ] | These guys have lie about a practice that is disapproved by the | chip's manufacturer and is not common (hopefully). First, this is a common practice with the 386, and I suspect that if it is less common with the 286 it's because the chips are cheaper. Look at ads in the back of most PC magazines. If you read the fine print many state clearly that they are using pushed chips, particularly the 386. Second, unless Intel has changed what they do for chip testing or unless one of my coworkers got incorrect information directly from Intel... the chips are identical, made at the same time one the same line. The 12MHz chips are tested at 12MHz, the 10MHz chips at 10MHz. Now, *if* a chip doesn't pass 12MHz but did pass 10MHz, you might get one which is funny at 12. I would certainly buy a full rated chip if it's available as an option, but only because I am conservative when given the choice. Any chip will run hotter at 12 than 10, but the ink on the case doesn't make the slower rated part run hotter. If the vendor did a good job of checking the chips and selecting those which will be reliable at 12MHz the machine should not have any problems caused by the chip running hotter than a rated part. I suggest that you call the vendor and politely tell them that there was a misunderstanding, and that you would like to swap the chip for a part rated for the full speed. There's a good chance that they will do it, although they will expect you to pay the price difference and shipping I suspect. From their standpoint you have a machine which is working fine and you are just upset about the label. I don't think that you have a problem, nor that they are as evil as you conclude. I hope that you are able to either work out a swap or become comfortable with what you have. It's a shame to get a new box and not like it. -- bill davidsen (davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen) "The world is filled with fools. They blindly follow their so-called 'reason' in the face of the church and common sense. Any fool can see that the world is flat!" - anon
rcd@ico.isc.com (Dick Dunn) (11/16/89)
phd_jacquier@gsbacd.uchicago.edu writes: ...a discussion with a vendor about using a 10-MHz chip in a 12-MHz system: > I called and they stand by it even though they don't tell you anything at > purchase time. Here are some excerpts of the phone call: > > Q: " It is not recommended to push CPU's beyond their guaranteed speed. > You should give me a 80286-12 if i paid for a 12Mhz system" > A: " Have you had problems? You have a one year guarantee anyway" > Q: " What if it dies after one year because it's been used at too fast > a speed?" > A: " If there is a problem because of the speed, it's going to happen right > away, not after a year." Let's try a contrived example: Q: "The tires on my car are not rated for highway speeds of 65." A: "Have you had any flats? The tires are warranted anyway." (I told you it would be a contrived example.:-) Q: "What if the tires give out because they're being used above their rated speed?" A: "If there is a problem because of the speed, it's going to happen right away." Of course, running a PC with chips outside spec is not (likely) a physically dangerous thing to do...but it certainly can affect the reliability of your system. Moreover, if there is a problem because of the speed, it will show up in one of two ways: - The system will fail right out of the box. - It will work for a fair while (perhaps a year?) but eventually fail as components age. There is a popular misconception that "no moving parts" ==> "won't wear out" There really IS something to worry about with running CPUs outside spec. Also, as I've commented before, if the board designers don't even stay within spec on the CPU--which is stamped with the right speed so any fool can see it--what are the chances they've cheated in other parts of the design? How much of your data do you want to bet that they got it right? The hope was expressed that this is not a common practice; I think that pushing CPU chips IS unfortunately common. -- Dick Dunn rcd@ico.isc.com uucp: {ncar,nbires}!ico!rcd (303)449-2870 ...Keep your day job 'til your night job pays.
johne@hpvcfs1.HP.COM (John Eaton) (11/23/89)
<<<< < < Recently i opened it to put in a 287 and saw that they use a SUNTAC 12Mhz < board with a 10Mhz cpu. I had noticed a minor performance difference with my --------- A 10 mhz CPU will normally be speced at 0 to 70 C and +-10% VCC. If you under-stand the speed derating and can guarentee a tighter environment then you can run the part faster. It is common for a chip maker to characterize the speed vs temp for a part so that they can test the parts at room temperature and a faster clock. That way the know it will work at the extremes. John Eaton !hpvcfs1!johne
akcs.amparsonjr@vpnet.UUCP (Anthony M. Parson, Jr.) (11/30/89)
I also am suspicious enough to ask about specs and ratings, before buying anything. I think the slower-rated parts are cheaper, that's how the headlines can grab you with the cheap prices. Another tactic I've seen: advertising a "31mhz" or "24mhz" 386 machine. In- quiring, since these are not the usual 16,20,25,or 33 Intel ratings, I find more than one vendor is actually quoting the Landmark program results, and running it on a machine that uses parts beyond specifications (at least one vendor) in addition. Thus a "31 mhz " machine, is actually a 20 mhz machine . "you pays your money, you takes your chances..."
karl@ddsw1.MCS.COM (Karl Denninger) (11/30/89)
>----- >Response 3 of 3 (6881) by _amparsonjr at vpnet.UUCP on Wed 29 Nov 89 09:22 >[Anthony M. Parson, Jr.] >(11 lines) > >I also am suspicious enough to ask about specs and ratings, before buying >anything. I think the slower-rated parts are cheaper, that's how the >headlines can grab you with the cheap prices. > >Another tactic I've seen: advertising a "31mhz" or "24mhz" 386 machine. In- >quiring, since these are not the usual 16,20,25,or 33 Intel ratings, I find >more than one vendor is actually quoting the Landmark program results, and >running it on a machine that uses parts beyond specifications (at least one >vendor) in addition. Thus a "31 mhz " machine, is actually a 20 mhz machine This is a common problem. We see it all the time, even with vendors trying to get us to carry their stuff! Needless to say, we don't even bother to talk to those slime... -- Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl) Public Access Data Line: [+1 708 566-8911], Voice: [+1 708 566-8910] Macro Computer Solutions, Inc. "Quality Solutions at a Fair Price"