• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

Dell Workstation Owners Club

Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
Joined
Oct 13, 2018
Messages
65 (0.03/day)
Processor i7-8086k
Motherboard ASUS ROG MAXIMUS X CODE
Cooling EVGA 240 WATERCOOLER
Memory G.SKILL DDR4 3200MHZ CL14
Video Card(s) EVGA RTX 3090 FTW3 Ultra
Storage WD Black M.2 NVMe 4x 500gb
Power Supply Dell 1100w (T7500)
Benchmark Scores https://valid.x86.fr/uwqpn1
Im running an h700 sas raid controller in my T7500...I currently let it be controlled by bios but I could easily change that to stand alone and see if I can push TS further.:banghead:
 
Last edited:
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
Im running an h700 sas raid controller in my T7500...I currently let it be controlled by bios but I could easily change that to stand alone and see if I can push TS further.:banghead:
TS doesn't mess with SATA clocks like SetFSB does. The report is that it raises the BCLK limit for SetFSB overclocks.

I did an LGA771 to 775 swap and while looking at the BIOS mod which changes the platform designator from 11=LGA775 to 44=LGA771 to recognize the new CPU. I wondered if something like this could allow unlocked Xeons to run single on a T5500 MB?
 
Joined
Oct 13, 2018
Messages
65 (0.03/day)
Processor i7-8086k
Motherboard ASUS ROG MAXIMUS X CODE
Cooling EVGA 240 WATERCOOLER
Memory G.SKILL DDR4 3200MHZ CL14
Video Card(s) EVGA RTX 3090 FTW3 Ultra
Storage WD Black M.2 NVMe 4x 500gb
Power Supply Dell 1100w (T7500)
Benchmark Scores https://valid.x86.fr/uwqpn1
TS doesn't mess with SATA clocks like SetFSB does. The report is that it raises the BCLK limit for SetFSB overclocks.

I meant SetFSB lol, sorry for the confusion.
 
Joined
Mar 8, 2018
Messages
350 (0.14/day)
Location
U.S.A.
System Name Dell T3500
Processor Xeon X5687
Motherboard Dell - 9KPNV
Cooling Dell U016F
Memory 12gb ECC 1333
Video Card(s) MSI rx480 gaming X
Storage 1tb WD blue
Case Dell T3500
EVGA still has some great deals on PSU. Started with 1000w units and has extended to others. Must be trying to clear old stock.

Pulled the trigger on 750 watt EVGA G1+. Could not pass it up at $60 (50% off). Gold rated, big single tightly regulated +12v rail, and long EPS cable so no extender needed for the T3500. Ten year warranty so hopefully it will last long enough for when I do eventually upgrade to a newer system.

[edit]
forgot link.

https://www.ebay.com/itm/EVGA-Super...-GP-0750-X1-/263997881387?hash=item3d777ffc2b
 
Last edited:
Joined
Sep 28, 2005
Messages
3,299 (0.47/day)
Location
Canada
System Name PCGR
Processor 12400f
Motherboard Asus ROG STRIX B660-I
Cooling Stock Intel Cooler
Memory 2x16GB DDR5 5600 Corsair
Video Card(s) Dell RTX 3080
Storage 1x 512GB Mmoment PCIe 3 NVME 1x 2TB Corsair S70
Display(s) LG 32" 1440p
Case Phanteks Evolve itx
Audio Device(s) Onboard
Power Supply 750W Cooler Master sfx
Software Windows 11
Good deal.

Too bad it's still expensive in Canada. Our market is too small and our currency dropped too much so sellers have Hay day here knowing they can price gouge
 
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
I have a question about Dell DCCU Dell Client Configuration Utility. I'm trying to load a modded Dell BIOS and it came with this program.
I got the modded BIOS file selected, made an EXE. file , and clicked Install.
No comfirmation, no progress bar, no error message. I started reading and there was a window that said 2 minute time out for system restart.
So what happens after 2 minutes? Does it restart? Does it abort the installation? Am I supposed to do something myself? How lomg does the install take.
This is for a Xeon swap into an Optiplex 380. except for a fast fan at startup unless I reboot and hit F1 at the Unsupported CPU message it works perfectly.
I need to know more about DCCU before I try this again. It didn't end well the first time.
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)
Dell T3500 :

80mm fans fit nicely. I do it to all of these that pass though my hands. Install in a 'pull configuration' so flow from front case fans is continued through the sink and toward back. For cooling, more CFM the better. Here I have used an old Panaflo high speed with hydro bearing. Nice and quiet at full speed.

My preference is to run wires behind the motherboard and draw power from the floppy wires with connector cut off. Who uses floppies anymore? Leave the wires long enough at heatsink end so you can easily set it aside when changing CPU. (optional: push bullet connectors at both ends for when complete removal is necessary)
12-volts constant works for me. You can also do the 7-volt trick by utilizing both 12 and 5 volt together, or just run 5-volts. Be sure the fan starts from dead stop at that power level. Not all do.

Mounting the fan is simple really. Slide one zip tie (seen in black) through so it sits flat between the fins. Then zip another (seen in green) to lock it on. Requires 6 zip ties total. Can only do three corners of the fan because of heat sink shape. Clip tie ends off flush when done.

View attachment 101849

At this time I like to install a small piece of foam on each corner of the fan, then a thick rubber band around the whole thing to put tension on the zip ties. Makes everything nice and tight which helps eliminate vibrations for quiet operation.

View attachment 101850

Yes 80 mm fan sits perfectly ....... however 90 mm fan can also be somehow mounted ...... 90 mm fan will give higher cfm.
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)
View attachment 104545

Here is my T3500/5500 with the R9 380x installed.

View attachment 104546

It’s a tight fit if you want to keep the RAM fan shroud.

View attachment 104547

I wanted to keep the original drive tray for now but it would not close properly with the video card in the PCIe x16 slot #1. Then I noticed you could remove part of the drive tray. Look close and you will see its held in by three screws. I removed that flap and clamped the SSD to the remainder with zip ties. Kind of ghetto but adequate for now .

View attachment 104548

Here is the piece of the drive tray I removed to make room for the video card. If you only have one drive on the tray you really dont need this extra piece. Removing it opens up a lot more room for a longer video card.

View attachment 104549

If you try to install a video card of any size at all, you will likely have to remove this plastic card retainer thingie. Its held into the chassis with a couple of screws. Easily to remove.

Good ...... and you can always zip-tie the SSD drive even with part of HD tray removed ....
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)
[edit]
Be sure to stay away from "N series" boxes. These are specific networking units that will not accept a Windows OS.

I just like to confirm that I just bought Refurbish T3500 having old XPDFK MB ....... its actually "N series" ....... but the seller provided me with Windows7 Professional X64 SP1 installed and working on it (which I upgraded to Windows 10 Pro X64).

I have no idea about how the seller installed Windows on this N Series ...... buts its working fine ......

So ..... installing Windows on N Series is certainly doable .......
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)
Does the older board still update to the latest bios ? Does anyone have any problems with the older board , Capacitor failure for instance . I have had two of the newer 09kpnv boards go in less than a year from the same PB12 issue ( last one i put down to VRM ) , so am wary .

Updating BIOS is no issue ..... I just updated to A17 on my T3500
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)
Yes. The PSU's for the T3500/T5500/T7500 are interchangeable. The wiring harness might not be perfect, but it should still be workable.

Is 1000 Watt PSU from T7400 ( Not T7500) compatible to T3500 system ?
I am getting one locally but cant decide because of confusion over compatibility.

Want to have higher spec PSU just in case I upgrade my GPU in future ?

Thanx in advance.
 
Joined
Nov 6, 2018
Messages
174 (0.08/day)

Awesome Mods .......

Nice mod :p.

I just did the same thing but I used the T5500 riser heatsink with fan assembly PN: 0W715F and a 5 pin dell splitter. I used the 5 pin cpu fan port on the riser card for both CPUs, but you could also use the case fan port if splitting.

The fan is like $15.



https://www.ebay.com/itm/Genuine-De...229017?hash=item2604058999:g:ugwAAOSw0RlbqSj1

Splitter is like $20 +s&h, but you can also use either use a 5 pin to 4 pin / molex, or just hack the cable.



http://www.performance-pcs.com/dell-5-pin-to-dual-5-pin-1-to-2-y-split-sleeved-fan-cable-20cm.html

20 USD for Fan wire splitter is hugely overpriced .......

It's tricky and not all PMW fans work. Weird stuff. Has to do with the way the fan controller expects to get signaling from the fan circuitry.

Yup, I always disable for home use scenarios as it's really only useful in professional environments.


Yes it's bit tricky to make 4 pin cpu fan work on 5 pin Dell fan header ....

Here is the Pinout Mod required .... You need to swap wire No 1 with Wire No 3 .....

image host


This video is in Russian ...... I do not know Russian ..... still the visuals are demonstrative enough to understand that you need to swap wire No 1 with Wire No 3 .....

For those who donot want to bother with Pin Mod ........ here is a cheap alternative ...

https://www.aliexpress.com/item/1Pc...442.html?spm=a2g0s.9042311.0.0.3da24c4dhAYxyG
 
Last edited:
Joined
Mar 8, 2018
Messages
350 (0.14/day)
Location
U.S.A.
System Name Dell T3500
Processor Xeon X5687
Motherboard Dell - 9KPNV
Cooling Dell U016F
Memory 12gb ECC 1333
Video Card(s) MSI rx480 gaming X
Storage 1tb WD blue
Case Dell T3500
I just like to confirm that I just bought Refurbish T3500 having old XPDFK MB ....... its actually "N series" ....... but the seller provided me with Windows7 Professional X64 SP1 installed and working on it (which I upgraded to Windows 10 Pro X64).

I have no idea about how the seller installed Windows on this N Series ...... buts its working fine ......

So ..... installing Windows on N Series is certainly doable .......
Thanks for the confirmation. As I understand Dell had to cripple non-windows bundled machines due to Microsoft licensing agreements.

No personal experience, but Windows on T3500 N series is certainly doable. Just not easy. One way is to change the motherboard. Another is change the service tag then do a factory reset on the BIOS. This page explains the procedure.
 
Last edited:
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
Is 1000 Watt PSU from T7400 ( Not T7500) compatible to T3500 system ?
The Dell workstation PSUs are modular. The entire harness comes off to adapt to the various computers they were used in. But I don't think there will be a harness for the single CPU T3500 to fit the 1000W PSU so much of it will be wasted.
Maybe with a T7500 harness you could use adapters to tap into it's power. But it would have 2x 8 pinCPU cables and 2x 8 pin GPU cables already I believe.
It's 9" long plus 2" for the harness.
The T7400 harness will have a 24pin ATX, and a 2nd 20 pin Dell MB connector for the 2nd CPU and FBDIMM memory, and a 10 pin connector for the optional CFX dual GPU daughter board, so as is it won't be very useful.
I think the dual GPU T5500 came with an 875W that's physically a better fit.
 
Last edited:
Joined
Sep 27, 2014
Messages
550 (0.15/day)
Does anyone know what clock chip use the Dell T3500 motherboard model 09KPNV rev A00?
 
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
SLG8XP519T But support is hard to find for that one.
The ICS932S421BGLF is supported by SetFSB and is the PLL for the T5500, and T7500. So if this method appeals to you a single or dual CPU setup on those should work. An SATA controller card is reported to be necessary to prevent OS crashes. The T5500 MB is a direct replacement for the T3500. Cost about $40. But the chipset might prefer RDIMMs.
https://www.overclock.net/forum/5-i...rclocking-dual-xeon-dell-precision-t7500.html
You might want to look at the Throttlestop Overclocking thread also. Lots of T3500 overcloking going on there.
https://www.techpowerup.com/forums/threads/throttlestop-overclocking-desktop-pcs.235975/page-21
 
Last edited:
Joined
Nov 6, 2018
Messages
174 (0.08/day)
The Dell workstation PSUs are modular. The entire harness comes off to adapt to the various computers they were used in. But I don't think there will be a harness for the single CPU T3500 to fit the 1000W PSU so much of it will be wasted.
Maybe with a T7500 harness you could use adapters to tap into it's power. But it would have 2x 8 pinCPU cables and 2x 8 pin GPU cables already I believe.
It's 9" long plus 2" for the harness.
The T7400 harness will have a 24pin ATX, and a 2nd 20 pin Dell MB connector for the 2nd CPU and FBDIMM memory, and a 10 pin connector for the optional CFX dual GPU daughter board, so as is it won't be very useful.
I think the dual GPU T5500 came with an 875W that's physically a better fit.

Thanx for the feedback info.

Really appreciate.
 
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
I came across a claim that RDIMM memory can run on an X58 chipset. This is at OCN X59 Xeon club on an aftermarket MB with an X5675 Xeon. The claim was for 4GB RDIMM modules with ECC running on ASUS X58.
You can see the controversy starting here.
https://www.overclock.net/forum/8-i...official-x58-xeon-club-1415.html#post27676896
But if anyone wants to try this away from the politics of OCN X58 Club please feel free.
 
Joined
Jul 5, 2013
Messages
27,513 (6.63/day)
I came across a claim that RDIMM memory can run on an X58 chipset.
Officially, Intel states that the x58 chipset does not support registered ram at all. Either that is a spoof post or there is some serious hacking going on to make it work.
 
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
Officially X58 doesn't support the 5500.5600 Xeons either and they run just fine. The memory controller is on the CPU and those do support RDIMMs. So I see it as a real possibility. But definitely unconfirmed. The hack would be running the dual CPU Xeons in the first place. It's possible they run as UDIMMS, or they actually run as RDIMMs, if they can run at all. It's not something I would put much effort into. But the fact that the X58 T3500 supports ECC is a step in the right direction.
 
Last edited:
Joined
Jul 5, 2013
Messages
27,513 (6.63/day)
Officially X58 doesn't support the 5500.5600 Xeons either and they run just fine. The memory controller is on the CPU and those do support RDIMMs. So I see it as a real possibility. But definitely unconfirmed. The hack would be running the dual CPU Xeons in the first place.
Thought I'd read somewhere that RDIMM's were not supported on x58 but are on 5500/5520 chipsets. Yet you're right, the mem controller is on the CPU. Maybe it is possible. This deserves more research.
 
Last edited:
Joined
Nov 6, 2018
Messages
174 (0.08/day)
Officially X58 doesn't support the 5500.5600 Xeons either and they run just fine. The memory controller is on the CPU and those do support RDIMMs. So I see it as a real possibility. But definitely unconfirmed. The hack would be running the dual CPU Xeons in the first place. It's possible they run as UDIMMS, or they actually run as RDIMMs, if they can run at all. It's not something I would put much effort into. But the fact that the X58 T3500 supports ECC is a step in the right direction.

As per Dell, T3500 can support only upto 24 GB RAM Max. But since the memory controller is on the CPU, perhaps it may be it may be still be possible to run 6 X 16 GB Modules or 6 X 32 GB Modules (if 32 GB Modules are available) if T3500 are upgraded with CPUs like Xeon X5680 (which supports upto 288 GB RAM).

It may be that since originally Dell released T3500 with only W35XX series processors, hence Dell T3500 Manual mentions Max RAM capacity of 24 GB Max which is the limitation of W35XX or W36XX series processors.

However, practically I have not tested any as such RAM modules I do not have these.
 
Joined
Jul 5, 2013
Messages
27,513 (6.63/day)
As per Dell, T3500 can support only upto 24 GB RAM Max. But since the memory controller is on the CPU, perhaps it may be it may be still be possible to run 6 X 16 GB Modules or 6 X 32 GB Modules (if 32 GB Modules are available) if T3500 are upgraded with CPUs like Xeon X5680 (which supports upto 288 GB RAM).

It may be that since originally Dell released T3500 with only W35XX series processors, hence Dell T3500 Manual mentions Max RAM capacity of 24 GB Max which is the limitation of W35XX or W36XX series processors.

However, practically I have not tested any as such RAM modules I do not have these.
We were talking about RDIMM's AKA Registered/Buffered RAM. As for your point, I have actually done a similar test. The T3500 will recognize and use 8GB modules, for a total tested amount of 8GBx6=48GB. I've not tested 16GB modules, but don't see any reason why it might not work.

Test post..
 
Joined
Jan 19, 2016
Messages
1,086 (0.34/day)
Location
South Florida
System Name BTXTREME
Processor QX6800 SLACP Core2 Extreme
Motherboard Dell 0WG864 LGA775 BTX
Cooling Dell T9303 heatpipe cooler, Delta GFB1212VHG 2 motor fan.
Memory 8GB Dell DDR2@800
Video Card(s) Sapphire Dual BIOS R9-285 ITX O/C 2GB DDR5
Storage Crucial M500 240GB SSD
Display(s) Dell 22" LCD
Case Dell Dimension E 520 MT
Audio Device(s) onboard sound with Logitech Z523 speakers
Power Supply EVGA B2 750W semi modular
Mouse Logitech wireless (two installed)
Keyboard Logitech wireless backlit
Software Win7-64, Throttlestop 6.00 overclock
Benchmark Scores 3DMark 11 P7644 (52% )In Win7 64, Firestrike 6892 ( 58% ) http://valid.x86.fr/l2j5p1
48GB is a known capacity of X58. The larger modules either didn't exist, or weren't tested, so they're not documented. The questions begin when running the 5500/5600 Xeons, with their RDIMM support up to 96GB (which also may not be an actual limit) onX58 systems. At OCN it's a controversy whether RDIMM can run on X58. The person claiming they do doesn't document the claim very well. I posted the question here because there may be someone who has access to a T3500, and some RDIMMs to try and confirm this.
The butting of heads over RAM issues is why I started the Throttlestop Overclocking thread since it's usually irrelevant to that method. But The RDIMM question has merit.
AFAIK RDIMMs run 2T command rate and the other timing remain the same. But I'm not sure of this.
 
Top