I use QTP3 Redimized, all of the improved trees and flora stuff, as well as 4096x4096 distant lod textures (though smaller normals). I have MMM and WAC (just the basic esp) active plus Armamentarium and other LL item mods, as well as the various road traveler mods (though Crowded Roads Revisited is set at the lowest spawn rates). NPC New Clothes and Cyrodiil NPC Remodeling Project are giving NPCs diverse outfits. I also have all of the UL mods active. And to definitively limit my framerate I'm using OBGE, though I don't know how that could contribute to vram usage. I understand this is a lot of stuff, though.
It started to get annoying as I noticed vram usage consistently hitting 1000-1300 mb while out in the wilderness in the past month or two, but last night it just floored me. I had installed part of QTP3 Reduced to see if it would help, and I noticed no difference, so my next step was disabling the UL mods, thinking maybe their extra textures were contributing to the problem. So I did that and did a run from the IC to Chorrol and watched the vram usage. As I approached Chorrol, it just about hit 1500 mb. And as this was happening my game became a slideshow, delivering a frame to me like once every five seconds. I guess the UL mods don't make any difference!
I've heard that QTP3, even Redimized, can be a huge drain. But this huge? I wouldn't be so skeptical if I didn't remember a while back when I first switched to Redimized--regular QTP3 was too much so I switched and did some other cleaning, getting rid of improved sky textures and hi-res tree billboards. I got it down to 700 mb at the time, at least, in a particular spot. Today if I go to that spot it'll be at nearly a gig of texture memory being used. If I load my current save in Chorrol it'll be at 900-1000 mb there. The only major thing I can think of that I installed since that wonderful 700 mb day is MMM, as well as a bunch of leveled list item mods.
I just wanted to share this and see if maybe there could be some mysterious explanation. I can accept that with QTP3 and other hi-res textures I might just be pushing things too far, but should it really be this bad? There are some locations where it might get down to 800-900 mb, but nearly everywhere outdoors it seems to get up to 1000-1300 mb, and as last night showed, apparently the sky's the limit

Load order:
Spoiler
Active Mod Files:00 Oblivion.esm01 Enhanced Daedric Invasion.esm02 TamrielTravellers.esm [Version 1.39c]03 IWRRetrofittedMaster.esm04 A_Bloody_Mess.esm05 Waalx Animals & Creatures.esm06 Natural_Habitat_by_Max_Tael.esm07 Qarls_Harvest.esm08 ShieldOnBack.esm [Version 2.4]09 Hemingweys Capes Improved.esm [Version 3.0b]0A Mart's Monster Mod.esm [Version 3.7b3p3]0B VASE - core.esm0C Armamentarium.esm [Version 1.35]0D Artifacts.esm [Version 1.1]0E John's Leveled List Overhaul.esm0F Cobl Main.esm [Version 1.73]10 All Natural Base.esm [Version 1.3]11 The Arsenal.esm12 Unofficial Oblivion Patch.esp [Version 3.3.3]13 DLCShiveringIsles.esp14 Unofficial Shivering Isles Patch.esp [Version 1.4.0]15 Knights.esp16 Knights - Unofficial Patch.esp [Version 1.1]17 DLCHorseArmor.esp18 DLCHorseArmor - Unofficial Patch.esp [Version 1.0.6]19 DLCOrrery.esp1A DLCOrrery - Unofficial Patch.esp [Version 1.0.4]1B DLCFrostcrag.esp1C DLCFrostcrag - Unofficial Patch.esp [Version 1.0.5]1D DLCThievesDen.esp1E DLCThievesDen - Unofficial Patch - SSSB.esp [Version 1.0.4]1F DLCThievesDen - Unofficial Patch.esp [Version 1.0.7]20 DLCVileLair.esp21 DLCVileLair - Unofficial Patch.esp [Version 1.0.6]22 DLCMehrunesRazor.esp23 DLCMehrunesRazor - Unofficial Patch.esp [Version 1.0.5]24 DLCBattlehornCastle.esp++ Cobl Tweaks.esp [Version 1.44]++ DLCSpellTomes - Unofficial Patch.esp [Version 1.0.1]25 DLCBattlehornCastle - Unofficial Patch.esp [Version 1.0.5]26 DLCSpellTomes.esp27 Cobl Glue.esp [Version 1.73]** Cava Obscura - Cyrodiil.esp** Cava Obscura - SI.esp** Cava Obscura - Filter Patch For Mods.esp28 Cobl Si.esp [Version 1.63]29 Global Chest 20 Portals Ayleid.esp++ All Natural - MMM Patch.esp [Version 1.3]2A All Natural.esp [Version 1.3]2B All Natural - SI.esp [Version 1.3]2C All Natural - Real Lights.esp [Version 1.3]2D Weather Debug Ring.esp2E Immersive Interiors.esp [Version 0.8]2F Immersive Interiors - Lights Addon.esp [Version 0.8]30 OBGE - Liquid Water.esp31 YetAnotherHotkeyMod.esp32 VanityCameraSmoother.esp33 ChaseCameraMod.esp34 FlyingCameraMod.esp [Version 1.3]35 P1DanywhereSittable.esp36 ImmersiveWait.esp37 DropLitTorchOBSE.esp [Version 2.4]38 Map Marker Overhaul.esp [Version 3.8]** Real Lava 1.3.esp39 Map Marker Overhaul - SI additions.esp [Version 3.5]3A Dynamic Map.esp [Version 1.0.1]3B Display Stats.esp [Version 1.3.1]3C MiniMap.esp++ Symphony of Violence.esp3D fwDropGold.esp3E Toggleable Quantity Prompt.esp [Version 3.2.0]3F P1DkeyChain.esp [Version 5.00]40 Poison Equipper.esp41 StarX Vampire Deaths.esp42 BNewShockBoltEffects20.esp [Version 1.2]43 MIS.esp++ Harvest [Flora] - DLCVileLair.esp [Version 3.0.0]44 MIS New Sounds Optional Part.esp++ Harvest [Flora] - Shivering Isles.esp [Version 3.0.0]45 Atmospheric Oblivion.esp46 AgarMoreVariedSpellEffects.esp47 Distant Chapel Bells.esp48 Musical Immersion 1.0.esp49 Dungeon Actors Have Torches 1.6 DT.esp4A Book Jackets Oblivion.esp** mz_Shields.esp++ Garak's Staff Replacer Fire&Ice.esp [Version 1.5]++ Garak's Staff Replacer Blood&Lightning.esp4B Book Jackets DLC.esp4C Knights - Book Jackets.esp4D GrimbotsSpellTomes.esp4E Harvest [Flora].esp [Version 3.0.0]4F Qarls_Harvest.esp50 More_Vegetables.esp51 Leviathan Soulgems.esp52 Alluring Potion Bottles v3.esp53 Alluring Wine Bottles.esp54 upperGothicClutter.esp55 ImprovedSigns.esp56 FarmersStrikeBack.esp57 CT-Com's Torch Compendium.esp58 Clutter Weapons.esp59 what.esp5A SlimeDoll_v1.0.esp5B equipablestuff.esp++ 1HweaponOnBack.esp [Version 1.0]++ Slof's Manly Stride.esp5C fishclub.esp++ MotionReplacer.esp5D IRaimFunnyItem.esp5E JustABox.esp5F Unlimited Wear.esp60 TTB.esp61 JQ&DM-ScriptedBackpacks.esp62 CET-Utility-Belt.esp63 qazFingerSnap.esp64 Slof's Oblivion Robe Trader.esp65 Mage Equipment.esp66 LSBSkullWeapons.1.esp67 SSEE.esp68 polearms_1.0.7_EV.esp69 Sin's Expanded Light Armor Kit [NPC].esp6A BlackGlovesEng_noNPCchanges.esp6B LBExoticAyleidArmorLLonly.esp6C ANBFaceCloths.esp6D moregems.esp6E The Arsenal.esp** Slof's Horses Base.esp** Slof's Extra Horses.esp6F The Arsenal - Leveled Lists.esp [Version 3.0.0]70 RealisticForceHigh.esp71 Mounted_Spellcasting.esp72 ClocksOfCyrodiil.esp73 The Imperial Water.esp74 Anvil_MorningGlory_Mixed.esp75 Wayshrines Improved.esp76 IWRRetrofittedLights.esp++ Life Detected - Skeleton - Medium - 1.esp++ Shining Creatures_DLCFrostcrag.esp++ Give Me My Shader Effects.esp77 PONLights.esp78 Enhanced Vegetation [150%].esp79 SwampGrass.esp7A diversegrasses.esp7B WAC.esp++ Mart's Monster Mod - Shivering Isles.esp [Version 3.7b3p3]++ Mart's Monster Mod - Slof Horses Complete.esp [Version 3.7b3p3]7C WAC - Birds&Insects.esp7D AliveWaters.esp++ Mart's Monster Mod - Knights.esp [Version 3.7b3p3]++ Mart's Monster Mod - No Bone Loot.esp [Version 3.7b3p3]7E Fish! - v1.1.esp7F Natural_Habitat_by_Max_Tael.esp80 Slof's Dogs.esp++ Mart's Monster Mod - Spawn Rates - Reduced Vanilla.esp [Version 3.7b3p3]++ VASE - Cyrodiil for MMM.esp++ VASE - Vanilla SI.esp81 PTFallingStars.esp82 Mart's Monster Mod - More Wilderness Life.esp [Version 3.7b3p3]83 Rainbows.esp84 PTAutumnTrees.esp85 QQuix - Rock, rock, rock your ship - V3.esp86 Shining Creatures.esp87 [GFX]_Initial_Glow-self.esp88 A Bloody Mess - Bloody Fights.esp++ ArmamentariumLL.esp [Version 1.35]++ ArmamentariumLLMagic.esp [Version 1.35]++ ArmamentariumLLArmaVendor.esp [Version 1.35]89 [Hexaae] Get Wet v0.92.esp [Version 0.92]8A SnArrowEffects.esp8B Mart's Monster Mod.esp [Version 3.7b3p3]++ Artifacts - ArmaCompleteAddon.esp [Version 1.0]8C Mart's Monster Mod - Farm Animals.esp [Version 3.7b3p3]++ John's Leveled List Overhaul - Vanilla Armours.esp++ John's Leveled List Overhaul - Cyrodillic Armors.esp8D Mart's Monster Mod - City Defences.esp [Version 3.7b3p3]8E Mart's Monster Mod - More Wilderness Life No Gates.esp [Version 3.7b3p3]8F Mart's Monster Mod - Extra Wounding.esp [Version 3.7b3p3]90 unnatural_aura_by_trollf.esp++ Adonnays Elven Weaponry for NPCs - Armamentarium piggyback.esp++ MMM-Cobl.esp [Version 1.73]91 Mud Crabs!_MMM.esp92 P1DlookHereYou.esp93 Personality Idles - Modified version.esp [Version 1.3]94 ArmamentariumArtifacts.esp [Version 1.35]95 Artifacts.esp [Version 1.1]96 John's Leveled List Overhaul.esp97 John's Leveled List Overhaul - Vanilla Weapons.esp98 Weapon Expansion Pack for Oblivion Nthusiasts.esp [Version 1]** Goblin Realswords+Tribal Shields.esp99 Bob's Armory Oblivion.esp9A AyleidMeteorIronWeaponsVANILLA.esp9B Adonnays Classical Weaponry.esp9C Adonnays Elven Weaponry for NPCs.esp9D Shields Of Antiquity.esp9E Loth's Blunt Weapons.esp9F Loth's Blunt Weapons for Npcs.espA0 phinix_dual-wield_imports.espA1 Ayleid Loot EXtension.espA2 PTArtifacts.espA3 WAC - TCOS.espA4 WAC - TCOS Shops.esp [Version 03]A5 xulBlackwoodForest.esp [Version 1.1.0]A6 xulCheydinhalFalls.esp [Version 1.0.1]A7 xulCloudtopMountains.esp [Version 1.0.3]A8 xulCliffsOfAnvil.espA9 xulAspenWood.esp [Version 1.0.2]AA xulChorrolHinterland.esp [Version 1.2.2]AB xulAncientRedwoods.esp [Version 1.6]AC xulPantherRiver.espAD XulEntiusGorge.esp** NRB4 Standard Road Record.espAE xulArriusCreek.esp [Version 1.1.3]AF xulRiverEthe.esp [Version 1.0.2]B0 xulAncientYews.esp [Version 1.4.3]B1 xulBeachesOfCyrodiilLostCoast.esp [Version 1.6.4]B2 xulBrenaRiverRavine.esp [Version 1.1]B3 MMMMWL-RollingHills patch.espB4 MMMMWL-TheHeath patch.espB5 xulImperialIsle.esp [Version 1.6.6]B6 xulFallenleafEverglade.esp [Version 1.3.1]B7 xulStendarrValley.esp [Version 1.2.2]B8 xuldarkforest.esp [Version 1.0.5]B9 xulLushWoodlands.esp [Version 1.3.1]BA xulSkingradOutskirts.esp [Version 1.0.1]BB xulSnowdale.esp [Version 1.0.2]++ Item interchange - Extraction.esp [Version 0.78]** Hemingweys Capes Improved.esp [Version 3.0b]BC xulColovianHighlands_EV.esp [Version 1.2.1]BD xulTheHeath.espBE xulBravilBarrowfields.esp [Version 1.3.2]BF xulRollingHills_EV.esp [Version 1.3.3]C0 xulPatch_AY_AC.esp [Version 1.1]C1 WAC - xulBCLostCoast.espC2 WAC-ULchorrolhinterland-patch.espC3 WAC-ULdarkforest-patch.espC4 road+bridges.esp [Version 4.6]C5 NRB4+UL-II Patch.esp [Version 5.0.1]** TNR ALL RACES FINAL.esp** TNR - ShiveringIsles.esp++ Hemingweys VAN NPC Capes Improved IC Guards.esp [Version 3.0b]++ Hemingweys VAN NPC Capes Improved Regional City Guards.esp [Version 3.0b]++ Hemingweys VAN NPC Capes Improved Legion Forester.esp [Version 3.0b]++ Hemingweys Capes for EDI.esp [Version 3.0b]C6 Molapi.esp [Version 1.0.1]C7 Faregyl.esp [Version 2.0.1]C8 Feldscar.esp [Version 1.0.9]C9 Vergayun.esp [Version 1.0.7]CA Feldscar+Snowdale Patch.esp [Version 1.0]CB Better daedric shrine Azura.esp++ Hemingweys VAN NPC Capes Improved Enemies.esp [Version 3.0b]++ Item interchange - Placement.esp [Version 0.78]++ Item interchange - Placement for Frostcrag.esp [Version 0.78]++ Cobl Filter Late MERGE ONLY.esp [Version 1.53]++ Hemingweys VAN Boss Chest Cape Loot.esp [Version 3.0b]CC Better daedric shrine Hircine.espCD Better daedric shrines malacath.espCE Better daedric shrines molag bal.espCF Better daedric shrines Namira.espD0 Better daedric shrine Pyriate.espD1 Better daedric shrines Sheogorath.espD2 Better daedric shrines Vaermina.espD3 Better daedric shrines Clavicus.espD4 better daedric shrines Nocturnal.espD5 better daedric shrines Meridia.espD6 Better daedric shrines sanguine.espD7 BetterDaedricShrinesMeridia-RiverEthe.espD8 BetterDaedricShrineVaermina-AncientYews patch.espD9 ImpeREAL Empire - Unique Forts.espDA ImpeREAL Empire - Unique Castles - All The Castles - Merged.espDB ImpeREAL City Unique Districts - All the Districts - Merged.espDC SB IC Palace Tower Light Mod v1.1 - Modified Version.esp++ ImpeREAL Empire - Unique Forts - Slofs Horses - By Xtudo.espDD 24HrArenaAliveV2.espDE TamrielTravellers4MMM.esp [Version 1.39c]DF ShiveringIsleTravellers.esp [Version 1.39c]** TamrielTravellersHorseTextures.esp [Version 2]E0 Crowded Roads Revisited.esp [Version 1.1]E1 Crowded Roads Revisited_ChorrolCheydinhal_5.espE2 Crowded Roads Revisited_GoldRoad_5.espE3 Crowded Roads Revisited_GreenRoad_5.espE4 Crowded Roads Revisited_YellowRoad_5.espE5 PTRoamingNPCs.espE6 VOILA.espE7 VOILA - Soldiers of Empire.espE8 Salmo the Baker, Cobl.esp [Version 3.08]E9 Atmospheric Loading Screens - Original Text.espEA ClassyClothingCompendium.esp [Version 1.2]EB Hemingweys Capes Improved Merchants.esp [Version 3.0b]EC NPC new clothes V2.6 Modified.espED Better Redguard v2.espEE CNRP Cheydinhal.esp [Version 1.0]EF CNRP FightersGuild.esp [Version 1.0]F0 CNRP Chorrol.esp [Version 1.1]F1 CNRP DB.esp [Version 1.0]F2 CNRP Brumav02.esp [Version 0.2]F3 UNKNOWNYMOUS Social NPCs.espF4 Idle Dialogue.espF5 WindowLightingSystem.espF6 Bashed Patch, 0.espF7 CSC RM CW EL.espF8 lumi_enchantments_subtle.espF9 Diverse Effect Icons.esp